I can’t be with the man I love.

I (25f) met a guy (20m) on a friend making app. we hit it off immediately and gained feelings for each other. One day out of the blue he ghosted me and I was confused as to why. I was so upset I tried contacting him in several ways, but he wouldn’t respond. One day I messaged him and asked what was going on and he told me that he asked his mom how much older of a person he could date and she said three years. I feel so pathetic but I really do love him and I want to be with him and I just don’t know what to do. All we have been doing is meeting up in his car and I just want so much more, but he keeps telling me that he doesn’t wanna hold me back from getting more. he says he loves me so much that he wants me to be happy with or without him but the only person I want is him. Whenever we’re together, it’s amazing and he’s so loving and gentle with me and I just feel so hopeless and don’t know what to do. I know that he doesn’t want anyone else but me but we just can’t be in a relationship. I just don’t know what to do.