Help!

So I've been talking to this guy for a while now and he's really nice really sweet and really good looking. I'm 17 turning 18 soon and I found out he is 27 I don't know if I should keep talking to him because I've never had a real relationship before and I know age shouldnt matter but he lives in Switzerland and I live in Essex. He always talks about meeting me in person and wanting to make love to me and I told him that I'm a virgin and he said it turns him on even more he sent me a picture of his penis and it's pretty big and I'm quite frightened by it 👀😁 and I just don't know what to do and I really don't want my friends to know. Any advice?