What punishment should i get?

Respected expert,
Regarding these two stories plz tell me should I surrender to the police for the crime that I had done in the past. I think I was a frotteur before somewhat 8 yrs. At present I am 28.
Story 1
In the busy vehicle, one lady came to sit between my laps (because the vehicle was so packed and the seat was wide). At that time, I felt so much sexual pleasure. During my college life (before 8 yrs,) we had to get stand on the bus. At that time college girls of my same age around 19-20 come tight to me and I felt sexual pleasure all the time when they pressed their back parts near my genitals. Since then I liked to stand on the bus rather than sitting as I got such opportunity of getting sexual pleasure without forcing them. The condition at that bus itself created the situation so that my genitals pressed against their back parts. Such habit discontinued in my life as I bought the bike. Also, during that 2-3 years period, I used to press my genitals with my relative (male of almost same age as mine) while sleeping at night. Both of us were wearing normal cloth. But he did not know about this. So in summary, I used to ejaculate wearing cloth and pressed my genitals without notifying the victims in the past. Today I am feeling guilty and do not like to do those activities. Am/Was I a frotteur? Should I get punishment for that?

Story 2
I started masturbation followed by ejaculation only at the age of 18. But ejaculation was possible only when i rubbed penis over the bed wearing my normal cloth. From age 18- 19 and around 10 month, i used to ejaculate playing with my niece and other children permitting them to play on my laps ( both children and me were wearing normal clothes). Then after i realized that this is bad and i stopped doing these things even though these children requested me to play with similar style. At that time i still remember that these children were very happy and i had done no harm with them. At present i am 27 years of old age, the children whom i used to masturbate have grown now, they all are perfectly healthy. I am 99.95% sure that they knew nothing about such incident. I respect the children . i want to save the children from such kind of abuse. But,When i hear about childsexabuse, i feel guilty about the act that i had done in the past. I swear i did not know that the act i was doing was a kind of abuse. plzzz give me advise that what should i do , how big crime have i done and what punishment should i get?