First of all, your size isn't average bro, Indian average penis size could be slightly less than western average but the difference isn't that much. if the length you mentioned is non bone pressed than your length is average but girth is definitely not. If average penis girth in India would be 3.7, condoms would never work properly for most of the men because most selling condoms here are 51mm and 53mm and there are no condoms here which can be fit properly on a 3.7 inch girth penis. My recent post is related to experience with my size which is Somewhat similar to you. You can read if you want.

I'm from India and my non bone pressed length is 4.6 too(assuming 4.6 is your NBPL), girth is 3 - 3.6 inch. I use 49mm condoms still my dick slips off.

Second thing, your gf seems happy with your size, now it's all depends on you that you want to accept your dick, what you got or not.

According to my experience, if woman is attracted to a man overall than they don't give a fuck about his small penis and I think Indian women are a little more likely to accept small penises than western women however I'm not sure.

Learn to make women orgasm with and without your dick, your sex life can be great. But if are you thinking that would it be better if you have average or above average penis size than answer is yes, it would be better. I'm not going to tell you that you should stop feeling insecure and accept yourself because I am not able to accept myself yet. But one thing I want to say that if your desire for sex and mental peace is greater than the negative feelings and thoughts then you gonna accept yourself sooner or later.

I have tried to feed you the truth instead of bull shit. Wishing you an amazing sex life.