I’d take a good look at your batteries. You say that you had performance and are now losing it. Perhaps your cells might be getting a little tired, and sag their voltage under current now. Are you experiencing a drop in range?
I used some cheap lipos for my first build from hobbyking. I was also using a vesc, a 4.12 from Enertion. The batteries were great when I first bought them, the board had a lot of punch. After a good amount of cycles, the performance dropped significantly, both acceleration and range. Built a new pack and had my performance back.
Best of luck!