I can't let myself go during sex anymore help

I've been with my husband since I was 16 I'm now 20 he is 23 over the past year I can't let myself go sexually anymore I don't want him to touch me we used to be very sexually active I miss him being intimate with me and I want it so bad but when he tries my body says no and I don't want it I can't let go anymore what's wrong with me sex is not good for me anymore cuz I won't let him foreplay IDK why. I'm still attracted to him It just feels different I can't even majority with him I feel awful I'm destroying his self esteem and our relationship I love him so much and want to be the way I used to again plz help no mean comments pls this isn't because of my pregnancy it started with my first pregnancy last year but went on after I had my first daughter and continues to go on