Help? I need some advise. My feelings are stuck and confused.

My baby daddy and I have been together for 5 yrs and we just separated about a couple months ago because of some relationship issue that we are having. We have 2 kids together. And so I have a best friend who I’ve known for 10 yrs now and he was always there for me when my baby daddy and I were having problems. And so after we parted I was just stuck and didn’t know what to do until my best friend reminded me that he is there for me and hes going to be there no matter what and so I kinda started falling in love with him. He has admitted that he does have feelings for me as well. He’s in the army so he doesn’t really message me that much anymore (he does when he has the chance) because he is getting ready to be deployed. Now my baby daddy is trying to make our relationship work. And that’s where I am stuck. I am starting to fall in love with my best friend but getting stuck with the baby daddy issue too because we have kids together. I just don’t know what to do. I just don’t want to make the decision that is going to make me regret it later in life. If anyone can help me with some advice that would be great.

Also when me and the baby daddy is together I always feel tense and I’m always feeling like I am upset all the time. But when I’m with my best friend I feel happy and stress free.