Wtf if going on

I’ve been masturbating for a while now, and get different sensations from penetration and clitoral stimulation, but both are still satisfying. I started with watching porn but no I’ve moved on to reading smut. My problem: when I use clitoral stimulation, I reach what I think might be a climax, but then I get over sensitive and it only last for about a minute. With penetration I feel like it takes too long. Either way, I never think I’ve experienced the big O or have came either. Can someone tell me what a typical orgasm feels like and if I have experiencing one yet?