first time out without baby!

So last night I attempted to go out without my son for the first time m. He is a month old! I left him with my mom so I knew he was in good hands and I was only gone for a few hours with my fiancé but I jut felt like I couldn't relax and really have fun. I was so upset and sick to my stomach being away from him. I don't know if I just wasn't ready or what I hope I'm not like this forever. I want to be able to enjoy my time with just my fiancé. Any tips or tell me your experiences? Thanks!