I'm in a very similar situation. Yesterday I was up against a full 7* nightsister team 8 levels above my own on the 2nd GW node. Tonight it was a lot easier though, and I've had weeks where I finished GW every single night. I guess it's just tough luck sometimes.
If you have 7-starred Bastila and a few other characters, you've already accomplished more than I did :) I just turned 70 and don't have a single 7* toon so far because I've decided to leave my top teams alone for now and work on my criminally neglected Phoenix crew. Incidentally, that seems to make GW a bit easier most of the time. I read that the strength of your opponents is based on your top 5 characters.
PS: If you invest more $ to play catch-up, I found the single best way to progress is to just buy crystals and use them to buy credits, refresh energy to farm gear, or refresh the shipments to buy gear for credits.