What is considered rape when your drunk?

I'm finding it hard to figure out what is considered rape, and I have too different situations that have happened recently that in trying to figure out the difference between. So I went home with this guy, quite drunk, and I vaguely remember having sex with him and regretting it the next morning. I don't remember how it happened but I do know what I get like when I drunk and I know at the time I would've been into it. He also didn't seem like a dodgy guy. I don't consider this rape. The other situation: I was sitting alone at night, quite drunk waiting for my bus, and this dodgy looking guy came up to me, and starting pouring me drinks of vodka. Because I was stupid and drunk I drank it. Then after a while I started walking back with him and a group of his friends appeared, he continued to pour me drinks (he seemed very sober and wasn't drinking himself). The next thing I remember is getting off the bus with then, then sitting in a living room with his group of friends and kissing the same guy I was talking to before (I hated it but was so drunk I didn't even realise what I was doing). The next thing I remember is sitting on the floor on my hands and knees in a different room with someone's penis in me, and sucking another guys dick because he was waving it in my face. I have no idea how many people had sex with me that night.i feel digusting. I've told one of my friends and she said this was rape. what makes the situations different I don't remember both?