having to move on

i recently broke up with my first love and it hurts a lot, i still think about him all the time. a couple days ago someone told me that thry like me and i didnt know what to say, because i really like him and care about him but my heart was still with my first love. i am currently putting so much pressure on myself to move on but i cant, and i feel so fucking bad for the other guy because i know what heart break and unrequited love feels like and i dont want to cause the pain of heart break and unrequited love.

what should i do???