I need to break up with my short term boyfriend

I met my partner at the end of July via internet dating. We have seen each other every weekend since and seem to be getting on really well. I was widowed 2 and half years ago and also lost my mum on new years day this year. I have seen a lot of pain and been through a lot. At the weekend my partner announced to me that he has huge debts and he could lose his rented home. I now feel as though I cannot carryon with the relationship as I want to enjoy my life and not get roped into his problems I have had enough of my own over the past few years. I have said that he needs to sort himself out and have put him in the right direction of where to get help from. As he lives 45 miles away I cannot just turn up after work and i don't want him to trail over here. I have put everything in a letter to him and was thinking of e-mailing it through tonight and then saying I will ring him later for a chat. Is this the right thing to do. I have made up my mind that I want this to end as soon as possible to stop either of us getting hurt any further. Help!!!!