Cum too quickly but used to take too long

So Iโ€™ve been with my girlfriend for a while and the first few times I had sex with her it would take a while for me to cum (probably because I was nervous) , but recently Iโ€™ve been cumming really quickly even when I try not to. Wondering if this is normal and if I can go back to not cumminv as quickly as well as being comfortable with her during sex.

I personally think itโ€™s a mental thing because when Iโ€™m sober I suffer the same symptoms. But when Iโ€™m intoxicated and free of all inhibitions Iโ€™m a Demon.