Sorry OP, best advice I could have given you was obviously to find great players, befriend them, and let them carry you through NM. My bad.
Oh come on now. I mean, if you're trying to claim there are only two choices:
1. get to the point where you are overgeared and overpromoted for Nightmare and then try to PUG it in random public lobbies with no coordination
2. find good players doing Nightmare and get "carried" by them
Then yes, I'd consider #2 a much better option.
Amusingly, this reminds me of stuff I see in WoW. I'm the leader of a 20 man guild that spends two nights a week doing PvE group on the hardest difficulty. We're #1 in the entire US on that schedule and 7th worldwide or something like that. And when I say "hardest difficulty" I mean "the best guilds in the entire world, period, still take 300+ tries on the hardest bosses, sometimes 500+ tries." In DA:I terminology I'm leading a group of people doing Heartbreaker, in effect.
But 99.5% of the raiding population (or something like that) is less serious/skilled than we are. And a decent chunk of that population tries to PUG the easier difficulty levels. The catch is that these PUGs have ridiculous requirements. Imagine that Bioware said "We tuned Perilous assuming you have a level 13+ character, level 13+ weapon, and 2 promotions per role." PUGs would say "LFM Perilous, must be level 17+ with a level 17+ weapon and 4 promotions per role."
Why?
Because they don't want to wipe. They want to try to overpower/overgear content rather than actually working together and having good people. And in WoW, you couldn't get that level 17+ weapon without doing Perilous in the first place! It's a Catch-22 in effect.
So what do I (and other raiders) tell people? Don't PUG if you're trying to break into the harder difficulties. Find a guild of people who you can work together with to overcome the challenges with coordination and skill. And, of course, expect to fail initially until people improve.
If you can point me to other people in my situation and gear/skill/experience level who are starting Nightmare, I would be happy to play (and wipe) with them. If you were playing WoW I could easily do that for you. But...it's not exactly easy to do that in DA:I multiplayer. It doesn't have the population, community, or recruiting tools of WoW. So the next best thing is just to contact *any* players I can who are doing Nightmare or above and try to play with them. That is doable and that's what I'm doing.
Also, you're misusing the word "carry." I'm only getting carried if four people of my gear/skill/experience could not make it through Nightmare. Note I didn't say anything about speed Nightmare runs or no death Nightmare runs or anything. Other people having better gear/more promotions/more experience than I doesn't mean I'm getting carried. See the difference?
I made this statement because the OP's post indicated he wasn't quite ready to be playing NM.
I don't disagree, but from my perspective (and presumably most people's perspectives) it looked like general advice for anyone rather than something specific to the OP. Hence my comments.
Seeing as OP mentioned he was getting KICKED in NM, I assumed he was stuck PUG'ing for the time being. I also assumed he had little to no promotions. Pugging NM, especially when OP doesn't have (level 15 purple) armor or high quality weapons would just be a waste of time. Of course if you are playing with someone who can carry NM, this is less of an issue.
I don't see how anyone is ever "stuck" PUGing. If you (general you) want to reasonably do Nightmare or harder, you're going to want to find other people rather than try to PUG initially.
Which is different than saying the OP is ready for NM in general, PUG or not. And he definitely isn't. He absolutely would be getting carried and I don't suggest he do that -- he needs to get his act together first.
Well done completing NM. But, to be brutally honest, you aren't going to carry anyone with that setup. Could you be helpful when playing with a team that would complete without you? Sure. Is that possibly fun for you and those who are carrying you? Sure. But that is very different from actually carrying(being able to complete with little to no assistance) and completing efficiently(time investment for EXP and gold/item reward)
I think you misread my statement. I was carrying Perilous Dragons. I certainly am not able to carry Nightmare at the moment, but I do think I can effectively contribute on several characters in Nightmare to the point of not being carried.
Inquisition armor looks better on the archer, imho. 
I didn't see any pictures of it here. Is there a good resource for it? Found this for one of the colors but annoying to try to track the different variants down it seems.
What I mean is, I'm level 20 and I have a level 13 bow and a level 12 piece of armor with level 10 accessories. No matter what I do, I absolutely can't find any good gear. I get some cool looking stuff for other classes but I tear it apart in hopes I can get materials to make better things for my class. You all insist that I DO get good crafting materials but I don't. I can't really craft anything besides T1 or T2 grips.
Yeah, you're nowhere close to being ready for Nightmare.
You need to be farming/grinding Threatening/Perilous more and open a lot more chests for gear. You don't need "good" crafting materials for armor -- in fact you want to use the worst crafting materials possible for it. If you don't even have enough material to craft tier 3 grips then...yeah, you need to salvage a lot more. Don't forget you can salvage armor upgrades and runes if they aren't great.
If you go to your achievements section, how much gold have you collected so far?
Also, like Proto is saying, you should be promoting. Every warrior you promote is like 1% more HP and 0.5% less melee damage taken. Every mage is 0.5% more damage and 0.5% less magic damage taken. Every rogue is 0.5% more crit and 0.5% less ranged damage taken. Even if you wind up having terrible RNG and can't get anything above a blue level 20 weapon or something, having 10+ promotions per class or whatever can make up for that substantially (rogue promotions are especially important, actually).
That said, if you want to keep your archer at 20 and try to farm Perilous for more/faster chests (at least for now) that also works...but you have a long way to go and need a lot better gear in general before you consider Nightmare.