If you are between 13 and 15, you are going to look different in a few years, so people probably wont recognize you.
Also, do you know how many nudes there are on the internet? No one will care about yours.
Most people don't even watch that sort of things. If you are walking on the street, no one is going to point you out and say "There goes the nude guy!"
The best thing now is to stop worrying and start working towards the future to make yourself a better person than you were the day before. You may also want to tell your parents, or teachers.
People make mistakes all the time. This has helped you learn and mature a lot.
I myself have made huge mistakes in the past (not like yours, but they may get me into trouble), but I have learnt that I need to stop worrying about other people and what they do.
There will always be bad things in life. However, if you are able to overcome obstacles, there is no reason why you cannot be a great person.
99% of the time, people worry for no reason and it just wastes time. I can say this as I once spent 5 months worrying about what happened due to my mistake, and nothing actually happened.
Spend your time on learning something new and become a stronger person.
The more tough situations you get through, the stronger you will be mentally, and that is very helpful in life