Help! Theres something wrong with me and it's ruining my sex life

Im a 20M and i struggle to finish during sex. When im with my gf i get hard (not horny) all the time but i feel so disconnected to it all. If Im honest i hardly get aroused at all anymore. When i was younger i used to masterbate quite a lot to porn, at least a few times a week but now i can go at a couple weeks without needing to get off. When it comes to sex im never really hard and i can get bored but i keep going for my girlfriends sake. It takes at least a hour to finish (if i do) by which point i think shes fed up. Throughout my teenage years i suffered with depression but within the last few months iv definitely made progress and feel a lot better. Could the depression still be apart of the problem? Im so confused with what to do and i can see my girlfriend is blaming herself.it would be worth noting we've only been going out a couple month and up to this point i had lengthy dry spell. Any help or advice would be appreciated