Math Partners with Ex, should I back off?

My ex broke up with me about a month ago and it’s my first breakup so I handled it kind of terribly at the start

First I asked her to stay friends but she said no a week after I asked to work on math work and she accepted.

I thought I was making progress because she lost the coldness she had when she talked to me but whenever I get a text I get excited and then I find out it’s math related I get depressed again and fall into the spiral of sadness.

I never contact her first she always contacts me but should I tell her we can’t be math partners and stop contact or should I just not tell her and then do no contact subtlety.

Help is needed I love and want her back and I feel like I’m losing time with every day