Background: It's been a turbulent 20 months or so. DP and I got together shortly after he split from his long term ex (the mother of his 2 children who he'd been with on and off for 11 years). To begin with it went really well and I felt so so lucky (had liked him for a while), he made me feel so special and we fell fast and hard for each other. Soon he was staying most nights at mine and moved in a few months later as he was staying with famly temporarily and it didn't make sense for him to rent a place of his own when he was already spending so much time at mine.
We had a few teething problems, different parenting styles, lack of space, money worries and clashes between dp and my son. It was pretty up and down with arguments and calm times but I loved him so much and really wanted it to work, we both did, so we stuck at it and it got a bit better.
Then about 6 months ago someone contacted me anonymously to tell me dp had been having an affair. she gave me dates, times and examples of when she had seen them together and what they'd been doing. I confronted dp and he denied it, said he knew her but they were just friends.
I asked to meet her and he said I could but it never happenend. there was always a reason why not. I even went to see her without him but chickened out of talking to her because she was absolutely stunning. She also had her children with her so I didnt think it was appropriate/ I tried to end it a few times but he begged me to let him stay. Itold him he could not have further contact with her and he agreed.
I just can't get it out of my head, I wish I knew the truth. We've argued, fought, talked and cried together about it. I think he has realised his mistake and doesn't want to lose me but I still don't know if anything happened between them. I'm tormented by images of tehm togther,when we have sex I imagine him with her, i imagine them cuddling and laughing together. I've tried to move on but I can't get past it.
I'm constantly wondering what he's up to, who he's with and before all of his I trusted him more than I've ever trusted anyone before. I just don't know what really hapenned, I want to believe him, especially over a stranger but it doesnt quite add up and there's always doubt in my mind.
So I've asked himto go and he's back staying with family while I try to figure out what I want. And now I miss him so much. I want his arms around me and fr him to hold me, I want to smell him, everything reminds me of him. I feel so low all the time. I want his beautiful perfect cock inside me 
He's staying near her but has promised he wont see her. He's calling and texting me telling me he misses me and asking me to take him back.
I can't bear the thought of him being with anyone else. and if we split up he soon will be. He's gorgeous, good looking, friendly and easy to get on with, it won't be long before someone else snaps him up. Andme? I'm shy and nothing special. Before I got together with him I'd been alone a long time and thought I always would be. The thought fhim happy with someone else while I'm alone tears me apart with jealousy.
So how do I know if we should be together? Is what I'm feeling just the normal grief at a relationship ending or a sign itshouldn't end? How much of it is rose tinted glasses> How much am I ignoring the bad times and just rememberinghow it was when we first got together> How much is jealousy? What if I'm alone for the rest of my life? And I don't want another relationship to have failed,
Please help. I thought a break would help mesee clearly but it's made me more confused