am i crazy?

so i’ve been talking to this new guy for about a month now.. at first he showed quite a bit of interest, but lately it’s died down. he doesn’t really text me a lot and is always with “the guys”.. he says he doesn’t really talk to anyone on his phone. anyway, just wondering if i’m being insecure or crazy because i kinda feel like he doesn’t like me anymore... i feel like he still has feelings for his ex, considering after she cheated on him, they remained friends and still talk... i know she doesn’t like me so i’m a little worried she could be talking to him in hopes of him not starting anything new with me.. i just don’t know.. i tried talking to him about it but he didn’t really have a lot to say... what should i do?