first thing is you need to truly understand what are the commandments that God set down for us, research this
then start you new life trying to follow/obey them.
If you have done the sinners/repent prayer and you truly believe in Jesus and have received the Holy Spirit, then you should feel much lighter (as if a great weight had been lifted off your shoulders) and your daily stress and worries are gone (this is what happened for me one year ago)
you have to genuinely want to stop sinning, and for me, that meant deleting all my porn and my browser history and uninstalling my video games (addiction is sin, including addiction to video games)
I just have 2 text based games left, that I play and try to moderate the amount of time spent playing them.
Satan is ALWAYS tempting you, and if you spend hours and hours playing games and not using that time to read & understand the bible and the scriptures, then Satan is winning.
You need to build a relationship with Jesus, and that takes time. And Jesus will test you many times. Try to remember that when you ask Jesus questions during prayer, he won't answer them in your time, he will answer them in HIS time, and this requires patience.
It is very important to forgive all those who wronged you in your life, you must remove the burden you carry around regarding the forgiveness of others.
Forgive all including school/work bullies, people who cheated/stole from you, old friends who stabbed you in the back, even a stranger who may have sold you a faulty car/motorbike etc. This link may help you: https://www.youtube.com/watch?v=3zyjsFJhUBw
Try watching/listening to some sermons, to gain more knowledge about Jesus and his ways. I recommend Derek Prince and Robert Breaker on YT