Dating widower

Hi,

I started seeing man who was one year widower in April 2016. We've been friends since college and briefly romantically involved then. Timing was never right for us. We've always stayed in touch over the yeas.,

So, the first 3 months he seemed he couldn't get enough of me. constant emails, texts and calls - he even told me he loved me after 2 months. We were together for anniversary of his wife's death (they weren't even married a year- she was pregnant and found out she had advanced cancer- their child survived but she didn't). He was ok for the anniv of her death. Things were great/ I saw him change and become so happy. At about 3.5 months, however, he starte to change. Few and delayed responses to emails and texts, very few calls. Always wanted to still see me, but there was a marked change in his behavior and affection. He told me his doc said these feelings were normal and to be expected. This all happened right before what would have been their 2 year wedding anniversary.

We've both pulled back over the last 3 weeks- I know he's down. I directly asked him about his feelings for me and if he'd like to continue seeing me and he said yes. I told him we should both take some time and "try" again.

My question is this: what's going on? Do I just leave him alone? He knows I'll be there for him if he needs me (we've been friends for over 16 years), but I just don't know my place. He knows how I feel-
Any advice? Thanks so much