I am so insecure and anxious i need advice!!!!?

ive been with my fiance a while now we have two children together and were getting married in 9months..i want to change but dont know how.its ruining both of our lives,i dont let him do anything..im dreading our wedding just incase girls come with little dresses on, i dont let him watch things with girls in..even if nothing of theres is showing she just has to be pretty and ill turn it off..ive just gave birth to our second child 2months ago..im obsessed with my weight.ive lost loads since giving birth but i still feel and think im disgusting..i cant live like this anymore, i trust him very much i dont think he will cheat on me i just dont want him to look at other girls..someone pleaseeee give me some advice..i want to be happy,i want to be excited about my wedding..thankyou