What is wrong with me

So I still really love my ex fiancé but we cannot be with each other for many reasons at this moment. We’ve been broken up for awhile and haven’t communicated with each other in about 3 months. Last time we communicated, everything was good, we left on good terms but I’m still in love with him. I know we aren’t together and he’s free to do whatever he wants but I don’t want him to move on and be with someone else. I know it’s wrong and selfish of me to think this way but the thought of him getting married and starting a family with someone else hurts me so bad. 😫💔 I still have this little hold of him in my heart that makes me want to keep him to myself but I know in the real world that’s not possible... please don’t bash me or anything, I’m just venting...