Welcome S.X.D!
Welcome to the GYE club!
It's a big step to post especially if you don't know will come out of it. Let me asure you, you are not struggling alone. The guys on the forum have been there done that and can relate to you.
Good on you for jumping right in and starting the 90 day count.
To answer some of your questions (although I know others can answer way better)
1- you are not alone in this battle anymore. We will be here during your good days to cheer you on and be here to lend a hand when it gets hard. Posting will also add an element of accountability
2- breaking free is possible! For some, breaking free can be a lifetime battle. Taking one day at a time and overcoming every urge/fantasy at a time
3- I have a יצר הרע and I see you have one too, I do not define myself with the actions that I've done. I'm definitely responsible but not defined by them. What can I do about the past? I can't change the past but today is in my hands.
Besides for our evil impulsive inclination, we have a yetzer tov, a neshoma that is literally part of Hashem himself that no matter what cannot get affected in any way what so ever.
Everyone has challenges, this is your challenge that Hashem gave you. It's not a contradiction to anything else that you have done.
Yes, it's a problem and needs fixing but you will get there!
Let this challenge rise you up not pull you down!
Wishing you much success here!
P.s can you filter your computer?
What else have you tried to stop?