Getting your story all written down and journaled so you can see it really helps you look at things from a different perspective. When you re-read what you wrote earlier in a different emotional state you'll be more clear-headed in your decisions. After that exercise focus on what you tell yourself you can't do without him and stop defending those thoughts. You can go on without him and you are a great person. It was his decision to cheat and leave because HE had low self-esteem.
Now you're unsure about his true intentions, does he want you because she died or does he really love you. No one but you can tell you, but you can decide for yourself by taking things slowly and pulling back as much as you can. Keep pulling back and focusing on you for right now. If he is willing to wait and understands your hurt and having hard time trusting him then I don't see any reason you can't reconcile in time.
Now you're unsure about his true intentions, does he want you because she died or does he really love you. No one but you can tell you, but you can decide for yourself by taking things slowly and pulling back as much as you can. Keep pulling back and focusing on you for right now. If he is willing to wait and understands your hurt and having hard time trusting him then I don't see any reason you can't reconcile in time.