RelationshipAdvice

Kim
I've been "dating" this guy from work for about 2 months and I'm so lost. 
When we first started talking he would always call me "sweetie/mamas" so cute, lately it has stopped. He posted "😍😍" on some girls Instagram pics and the girl on his. 
He's 27 I'm 24. We've had sex 2 times when we first started to talk. 
I have a feeling he's "talking" to other girls but isn't honest with me. Idk what to do. He's a sweet/nice guy and has said "I'm not in it to play with your heart" or "I'm not gna hurt you" what do I do? Am I over reacting because of my past? I mean he knows how bad my past relationships were, do I give him the benefit of the doubt..?