Am i weird ?

Hi, i'm 22 years old, currently attending college, overall i have a good life, i've good friends, travel frequently and i'm having a girlfriend for 6 months now.
I can share everything to my girlfriend, we're having a great relationship (the emotional aspects). Both me and my gf agreed that we dont care about physical appearance,
but i dont feel excited or able to have a proper boner when we get intimate (Even though she looks amazing naked).
It take me even longer than her to reach orgasm than her (And i have to fantasize about something else to reach orgasm - which i feel really guilty about)
When i'm alone, i usually get these random arousal moment and constantly thinking about sex. However when ever we get intimate, i lose interest and i does not want to do anything anymore. I can see the worried and disappointed look on her face when she cannot pleasure me thinking that it's her fault, but i feel the problem is with me and i'm guilty about it.

I feel so confused, i'm healthy, sociable, i cannot identify what is wrong with me.
I started watching porn at 12 or 13, i dont know if i'm heavily addicted, i watch it once every 2-3 days (but 1 session usually last 1-2 hour, i constantly search for new content) and i masturbate every 1 or 2 day. Most of the time, i do it when i'm free and it feels like a routine.

I read online that masturbation is considered healthy by doctor. I'm so confused, i keep thinking something is wrong with me.
Am i a porn addict ?