Cleo, I'm sorry you're (understandably) hurting so much! I hope that you will find some comfort in finally having some clarity about the situation and from the loss of the anxiety, even though that cannot take away the hurt.
And NYC has a point that you did the best you could with the info you had. You could have not believed him, given in to your doubts, but I'm not sure that you would have ended up in a better place, either in the relationship or afterwards.
Thank goodness your health turned out ok, and I'm sorry about your dad as well. I lost my dad a few years ago after almost 2 years of illness, so I can easily imagine how stressful your situation may be for you.
And I hope you're able to be supported by some of the other people in your life. Not that I'm saying AT ALL that they are replacements or anything like that, just that for me knowing that others still care provides some comfort in the face of loss.