G spot?

So i’m not at all new to masturbating. been doing it for like three years, i did however just recently discover the inside of my vagina and wow is it a wonderful feeling.

basically i stick my middle finger as far as a can and curl it really fast, it feels amazing but only for the first 15 seconds or so. which is totally fine, but my question is- is that actually an orgasm or is that just it feeling really good. if so how do i reach g spot orgasm? i’m over here thinking it can’t feel any better than when i first put the finger in, i feel it a bunch in my breasts when i do this too. anyone can help?