Love??

I am falling in love with my boyfriend, we have had sex a couple times now and the last time he told me he was falling in love with me. He’s said that a few times but i cant say it back. Physically can’t say it back. I think it’s because i fell in love with my ex a little too soon and then found out he had been cheating on me with multiple people. I told him about all of it and why its hard for me but i wanna be able to tell him how im feeling without hesitation or anxiety. What do i do? Please help!