What to do if you fall behind as Tristana ADC?

Let's say I lose lane and tier 1 turret, and the enemy bot lane can easily 2v2 me and my support every time. They decide to head on over and push mid down, and my team pretty much just loses map control right down to the dragon. What do I do because my team is often gonna resort to trying to force fights, and I'm not sure if I should be with them or just trying to farm. Obviously I need farm but I don't wanna lose more turrets because my team gets wrecked. Another big problem I run into is every lane is pushed so far out I literally can't farm waves or else I will die in the process, tristana auto-pushes waves too so it's not like I can really freeze it or anything. Should I just resort to taking jungle camps whenever they spawn? What if I have a stacking jungler?

So worst case scenario my team is getting snowballed on HARD how am I supposed to play it out to turn things around? I've checked out plenty of sites/guides but there's nothing that covers this kind of scenario so I'm hoping someone here can help me out.