Do I suffer from some disorders?

I am 21 year old girl doing my post graduation away from my home. I am staying as paying guest with my friends. I am very much confused about my way of dressing and my likeness towards some type of dresses. I am a little fat girl and my height is 164 cm and weight 56 kgms. While I was doing Plus-Two I started wearing jeans and casual pants. After that I started wearing tightest jeans and now my problem is I cant avoid them. Everytime I want to be inside them. During night time while sleeping too I will be inside them. My friends told me that I have some psychic problem that is why I wear them. They told me that jeans I am wearing is forming many wrinkles around the zip region that is the crotch region as well as the backside below my s. But I still wear them. Now the problem is with my tight white pants I wear during night while sleeping. I like them to wear without washing and so its some regions became yellowish due to sweat aculation. Seeing its tight wrinkles and creases I feel ************. But I don’t express it to my friends. Whenever I put my hands inside its pockets (even during sleeping) they tell me to free the pockets but I cant. Pockets are the region I fond most. It is the region where stitching go off soon. What is wrong with me?