REALLY IN NEED OF SOMEONE TO JUST LISTEN AND GIVE ADVICE 😭

For awhile now I've had this feeling now that my boyfriend has feelings for another girl he use to date a while back. And today he told me the truth that he thinks he does but he loves me and doesn't want to be with her. He doesn't know why he has feelings and wants them to go away but doesn't know how to make them go. He's a really sweet guy and never does anything to hurt me and is such a gentleman and I absolutely adore him but I'm scared one day he will slowly lose feelings for me. I know I don't need to worry about her because she doesn't feel the same for him and she has a boyfriend of 2 years but it doesn't help that they are good friends. I know he won't try and do anything with her but I am just so so scared he will lose feelings for me and it hurts that a small piece of him feels for her when he doesn't want it to and I am just a mess and don't know what to do.