Meeting someone you don't know is NEVER a good idea.
People can seem very nice on the computer and be totally different in person. They may not even be who you thought they were. It is important that you are very careful who you accept requests from and what information you share with someone you don't know.
Its never too late to tell someone what is going on. If you have sent pictures of your private parts to someone, it might be embarrassing for you to say anything, but don't keep it a secret. Tell a responsible adult, perhaps your Mum, Dad or guardian.
Remember, if you feel embarrassed to tell your family you can ALWAYS contact the Police on 101 or 999 in an emergency. We are here to help you, not to make you feel embarrassed or ashamed for any decisions you have made.