I would definitely quit Jiu Jitsu! I am no expert but I think you have been very lucky, that you havent had more symptoms from 13 concussions - but you risk getting long term problems. I understand that you love it and dont want to quit, but I would really consider it it is worth the risk.

I have had very big problems from only 3-4 minor/moderate concussions and even minor hits sets me back.

If I was you I would focus on good sleep, a vitamin regiment, avoid alcohol and articial sweeteners, eating healthy etc, and enjoy your life and activities that doesnt involve risk of hits to your head or jolts.

I hope the best for you.