Some sexual thing I did in my childhood is killing me

Hey everyone... I really need your help.. When I was 12 or 13 , I just touched my penis to vagina of 4 to 5 year old girl who was my neighbour. I had no idea about whether it's wrong or write at that time... I was just curious and only fear I had was what if my parents come to know about it... Am a medical student and when I was reading sexual offences in forensic medicine, It happened to read about rape and all.. Till my 22 yr of age, I never thought of this and it never came to my mind. But when I started reading about sexual abuse on children and etc, I started feeling even I have done this and I started comparing myself to rapist. And I started thinking I don't deserve to live because am really not that kind of person and even now whenever rape happens on any girl, when media projects that or someone put as whatsApp status , I feel like killing myself. I want to come out of this.. It's been more than 10 years iam suffering from this thoughts... I want to enjoy ife and do very well in academics and profession... Is there anyone who has same experience or similar and s there anyone who can help me on this... Please please I really want my life back... Please help me