My heart is broken.. give me advise please?

ni

After the 3rd time me and my bf had sex... he started to act distant .. my heart is really broken.

I tried to talk to him in general, hes texting me less.. and seems he’s not interested..

How I knew he’s not interested, since the last time we had sex.. he act as if he doesn’t really care.. his way changed... beside he’s super super active now on social media and ignoring my texts purposely.

What should I do?