Tight situation, what should I do?

Tight situation, what should I do?

I met this guy during my undergraduate days at Uni,we started dating and things were okay but not perfect because he was broke, but that didn’t stop me from loving and believing in him. Fast forward to 2 years ago when I left for service while he remained in school due to some issues, I met other people who were interested in me but because of him and my decision to remain faithful I didn’t have anything to do with any of them not even the one that was willing to offer ‘heaven and earth’ just so that he can have me as his partner. To cut long story short. I found out he cheated on me with a girl and when I asked him he wept bitterly and apologised for his actions so I had to give him a second chance but the problem now is that since then he has been acting funny and the most painful aspect of it is that he borrowed money from me(my savings) to start up a business which we agreed that he will pay back because the money is meant for my further studies but till this very minute he is reluctant to do so and I have exam to write which I can’t sit for if I’ve not paid my fees, but one of the persons that’s willing to give me the money is asking for sex in return. This man has the money but he said he can’t give it to me just like that because I declined dating him in the past because of my boyfriend. Pls I need your sincere opinions I’m really desperate at this point because I can’t imagine coming this far and them watch everything crumple.