It seems like I constantly go up against big turret builds, and I have a real problem surviving them. Granted I'm still new and learning, but what kind of counters are there for the big turret builds?

Bring lots of guns.

Even 2 attack ships can put a lot of hurt on a low-agility turret if you can get a bunch of them pointed at it at the same time.

Lots of red dice. If you want a list that is built only for the purpose of anti-turret duty, I would probaly run 3 bwings with HLC and FCS and slow roll to stay in arc and stay at range 3 as much as possible.

While this list works as a can opener, it will founder against high mobility lists and arc dodgers like interceptors and a lot of other things if you cannot kill them before you they close range, but if you just want to kill a fat turreted ship, that ought to do it.

Tie swarm is a fine option as well, probably one of the best all rounders

4 xwings can do a pretty good job, especailly Tarn with R7 and a rookie with the stress bot (R3-A2)

when you start stressinig a big ship, it gets un-fun for them real fast

crits are rough on big ships too, so anything that inflicts crits can be good, I also like prox mines as a counter for large base ships.

bear in mind, you still have to deal with the escorts, not just the big turret.

I'm going with 4 Tie Bombers w/ ordnance and bombs. I've heard of some people going with lots of Z-95's and Concussion Missiles.

Lots of B-wings are a popular choice, too.