need some help

You shouldn't feel bad, you haven't done anything wrong. Seems like you should tell P you don't want his pictures (I'm assuming you're pursuing this C guy?)

yeah last time p sent me a photo was tonight i never asked for it but he knows what happens when he sends stuff like that

Have you sent anything back tonight? I wouldn't if you haven't already. Instead tell him that while you're perfectly happy being friends and all but any pictures like that that you don't ask for wont be ok and that there needs to be boundaries within your friendship. It's best to just not react to these messages if you don't want to - you aren't obligated to take your top off or anything at all. I know it might feel weird and awkward to tell someone you no longer want to receive their sexual posts but if you are serious about getting with C (or just don't like P's images anymore) then it's what you have to tell them. If they keep doing it then perhaps tell someone. Again, I don't know what your intentions are or your full story so this is just some advice from what I have read, but it seems that you no longer want to get these pictures and you no longer want to have to respond to them either.