I'm an Archer too, so I know exactly what you mean. Heres a few things I learnt over time:
Make sure you learn cure from the conjurer class, it doesn't provide you with much health but its recast time is very fast and it will keep you alive for a couple of hits.

Stone skin is also a useful conjurer skill, it'll block the first few hits you get or if the mob is weak it will block all hits for about 4mins.(You need to cast this before every fight).

When ever you successfully land bind, change target and pull the rest of the mob away from the bound enemy. This stops you from being hit by its long range attack and also keeps it bound for like 30secs. Hitting it again unbinds it, which is really annoying.

Spam Wide Volley, I dont think its as strong as puncture but at least it hits multiple enemies, giving you less work overall.

I've noticed that after patch 1.19, mobs have been given specific territories. Pulling the mob out of these territories will cause them to loose interest with you, they will stop attacking and head back in. This will give you a chance to reapply stone skin and cast a couple of healing spells. But dont take too long because their health will start to regen.

If your still having trouble with 3 stars then try upgrading your gear....but that can be expensive.

I hope what I mentioned helps.