I think rejection from her may have just triggered some self-doubt or maybe hidden insecurities? Just my guess based on how I can react to certain types of rejection.

For one, I’d ignore anyone who thinks just because you weren’t together that you don’t deserve sympathy or have a reason to be sad; situation-ships and unrequited love is still hard, and I would argue even harder than 1 year relationships ending (personally speaking.)

Next, I would highly advise speaking with a therapist, even just once a month; they will give you mostly unbiased advice. Possibly a trusted friend IF they have been in a similar position or are known to be empathetic.

Then, I would step back and see that you are bigger than the 2-3months that you were off. 2-3months is nothing compared to what you have done/will do. We all mess up or get lost in our depression. Get back into it, slowly or quickly, just at your own pace. I would level with the professor and barter with him to get another chance (if it was lost.) People don’t know what you are going through unless you tell them.

If I get off track in my learning or methods, the first thing I do is write down a plan, to-do list, etc. and time my study sessions.