Okay, great information!
Honestly, you moved up in weight way too quickly. I know that you are eager to make gains, but with hanging, the most important thing is to get your technique right and to move up slowly. If you push too hard too fast, you end up with issues.
If you continue to have problems with slippage, I would suggest you cut down by 50% and only add a few pounds per week from there, until you reach fatigue in your first or second set. You have to be a bit patient as your body adapts. It will serve you better in the long run.
Lastly, please do not hang in pain. Do not fight it. If it is too much to handle, reduce the weight, or stop the set altogether. Your number one priority should be safety.
I am sure you will figure it out eventually.
Best of luck.