Not sure what to do…

I have been seeing this guy for 6+ months. We have been taking it very slow because I haven’t wanted to jump into anything serious as I dont feel ready and haven’t done since me and my ex of 8 years broke up - he knew all this… the last month he has been really banging on about a proper relationship and moving in although I have told him multiple times I don’t want to… the trouble is I had a lot of financial difficulty when I met him and out of no where he helped me with a lot of debts and bills…. I am extremely grateful for everything he has done and I have every intention of paying him back but I can’t afford to give him it back all in one go and want to set up a payment plan with him monthly but the trouble is I don’t want to see him anymore as he is becoming really forceful and full on which is putting me off big time but I feel I have a hold because of the money I owe him 😓 can anyone advice on what to do? I think if I call it off he’s going to turn nasty about what I owe him and ask for it all upfront which is going to be impossible!!