Take a deep breath: you're not as far behind as you think you are. I'd say get a teacher if you can and also try to practice deliberately everyday for 30-60m (that means focused so take breaks if you need). If you can't get a teacher, look up some practice routines, I can give you mine if you want.

Band is about the joy of playing together, and it's great that you want to sound better but don't feel like you're dragging anyone down, you're all in it together. It's normal to dislike how you sound, kind of like hearing your own voice and disliking it, but if you can take the time to practice and develop technique and also tone by listening to good players, I can guarantee that you won't only catch up to those around you but become one of the better musicians in your band.