I’m gaining weight smhh

When I started lifting weights in December I started to add protein powder to my banana smoothies and I have one almost every day. Am I gaining fat?? Im 156lbs right now and I was 140lbs in December that’s literally the complete opposite of what I wanted 😩😩😩 I don’t want to get fat but I been working on my glutes legs and arms. I did take a 4 week break from weightlifting in Jan. I feel big asl now wat am I doing wronggg Idek if my butt getting bigger.

Help mee how do I lose weight now