Lots to unpack here

Trying to make this as short as possible there’s so much to unpack here. Back in July a guy I’ve known for 30 years, hooked up with at various times in my life and even got pregnant by showed up at my work. He had a child with a roommate of mine 20 years ago and they haven’t spoken in many years and he heard she had cancer and he wanted to know if I knew anything about it. The second we saw each other the chemistry was there . Crazy chemistry . I have been in a shitty marriage for 15 years, he’s been with the same girl on and off for 30 years .. he was always a huge player. We started texting and had deep, personal, meaningful conversations and shared everything, he’s in a deep depression, I ended up leaving my husband in October ( nothing to do with him- but he definitely gave me the motivation to finally leave), he never asked me to leave my husband for him. He’s told me he felt like god had a plan for us, he wanted me to be patient with him… then he will just ghost me for weeks at a time ?? I went to Vegas in December when I got off my flight and turned my phone on I had about ten texts from him panicking that I wasn’t answering him ( this was after two weeks of not hearing from him) he said he was crazy for treating me the way he did, he needs me in his life blah blah . 48 hours later .. another week with nothing he does this to me constantly. This last time it was 3 weeks we went without talking and I saw him and he looked awful ( he didn’t see me) I couldn’t stop thinking about how sad and pitiful he looked for days so I reached out and things went back right away - he missed me , thought about me everyday .. I told him I couldn’t do it anymore and I was talking to someone else and he had a fit told me he loved me- but then says he doesn’t care go f* that dude and now isn’t talking to me again ??? I’m 45f, he’s 50m we have not had sex we saw each other like 4 times , fooled around nothing serious he asks to see me all the time then NEVER follows through I feel like I’m going fucking crazy???? HELP