Dear Raju Thomas, for a satisfactory sex life minimum 2 inch penis size is enough with erection. as you said it is 3.75 means you are having 1.75 inch extra or more ---- without erection penis size is not to be considered in any way the penis size varies in different geographical areas as the average height varies . simple answer to your questions is
1) yes you can marry and satisfy any girl with this size
is not related with penis size it is your sperm count
decides your ability to make any lady pregnant hence here nothing to worry.
3) flaccid penile length is unimportant and when erect 3.75 is OK and sufficient for both satisfaction
hence don't try any so called medical treatment as there is no proven authentic treatment for penile enlargement.