<human>: Can you summarize the given text in a few sentences?

So I (20/F) have been going through a rough time in my life and have been dealing with depression. I have been posting some sad things on my Twitter Instagram etc and my ex (22/M) has started to notice so he decided to text me last week to see if I'm okay and he really helped me out and gave me the best advice because he knows exactly what I'm going through. It was really comforting to know he cared and wanted to be there for me after all we have been through. 
Problem: He has a girlfriend (20/F)  he is absolutely head over heels for and I would never want to jeopardize that. (Which I told him) I also have a boyfriend (23/M)  who I do love very much but we have going through a rough patch and are currently taking a break. Deep down I love him but I'm having conflicting feelings and he doesn't really understand or connect with what I'm going through with my depression and anxiety. 
 Soooooo I'm starting to have feelings for my ex again and I get butterflies in my stomach every time he texts me. He checks in on me almost everyday and we just have long conversations about life and I just connect with him so well. I know he doesn't feel the same but why does he continue to contact me to make sure I'm okay and how I'm doing? 
Maybe I'm making this all up in my head. Maybe I'm just remembering all the good times and feeling we used to have.  I just want advice on what to do and if anyone has gone through the same sort of thing? 
Thank you.
<bot>: talking to my ex and I'm starting to have feelings even though we both are in relationships. What should I do?