The fact that you want to be pure should give you a great feeling of pride. Daven to Hshem that He should erase your memories and with time they will fade and you will not want to do anything else to soil your beautiful neshama. You sound like an amazing person and your desire to do teshuva, to fill your life with kedusha is so inspiring to me!!!!
Also, very important, unless you need it for parnassa, just access the Internet in a public place, like a library, etc. Take that (technological) pollution (as much as is possible) out of your home. It really makes your home so much better and you feel free! Hatzlacha Raba!!!