As a heavy pvper I wanted to add to this. When I first hit 50 with my sharpshooter spec and went to Warzones I felt super weak. Yeah I might get a large crit here and there, but most of the time it seemed like "hey look at the guy in cover, quick get him"
And having played a few classes, we are squishy. Very squishy, If you have a melee on you can't ignore him. CC, run him through your teammates, whatever.
I personally went Dirty Fighting and really enjoy it. Once you learn to manage your energy, you can be a force to be reckoned with. My personal experience is top 3 in Damage, Kills, Killing blows. (and this is without bio consumables)
I still use cover to throw an ability out here or there or drop in just to knockback. It's just about staying mobile.
So, stick with it find a spec that works for you, and have fun. The most important thing you need when playing isn't a super spec, or epic gear. The most important stat you have is your personal awareness. Don't get tunnel vision, don't get pulled off a point you're defending. Be aware. It'll change your game.