What should I do?

A few years ago I was inrelationship with my girlfriend for 2 years.
I have had homosexual experiences before meeting this girl, during my high school years.
During the two years with my girlfriend, at some point, my partner from high school (m) came in contact with me again
He tried to start seducing me and I ended up having s** with him.
Immediately after having s** I felt extreme guilt of what i did and I was scared to hell that i might catch any kind of STD. I was so scared and emotionally down those days that i had an emotional break down I lost my s*** and cried. My parents figured out that somethin is wrong and i had to tell the truth
I was afraid and I lied to them that my friend(m) forced me into the s***** acts… just to put the blame on him. Nothing criminal related happened. My father just got mad at my friend and me but he blamed my friend more cause of my lie.
My girlfriend found out the story from my cellphone chats and i said the same lie to her

Now it’s been a while from that time. Everybody is living their own lie but i still carry the guilt of the lie.
Please understand i live in a country that homosexuality is a serious crime in their religion and i was teenager back then

What should I do now to get rid of the guilt