Failing rebooting

Ok , so let me introduce myself first. I am tennager ,and I have struggled with porn . I was watching porn and masturbating daily, and 5 months ago I started to try to quit it but I entered into another cicle than I cannot escape, and I am desperate. What it happens is that I relapse, than I stay a week strong, without relapsing and then the thoughts become so powerful, and the stress level is increased and it happens that I remain home alone or I get to see a nude image maybe on my friends phone or someone else and guess what? I relapse again and again and again.
And I have another BIG problem. I have tried to install a porn filter: guess what? I am a computer science student/future programmer and my mind is set to watch for bugs in a software or for ways to overpass it and , it happens that I find ways to overcome it.... I also tried to install an app on the phone named applock, and with this app I've blocked my internet browsers, my google play store my facebook and another app from where I could acces porn. It was fine but I found a way to stop the software , and I here is another relapse.
The second problem is that now I don't have a desire for real women, just for porn.
And the third problem is that when thoght to relapse comes, the things happen something like that: the porn thought comes, I try to push it, ignore it by then something happens. Maybe a I get a bad mark at school or someone screams at for no reason and because I am pretty sensitive man, sometime I fell bad but sometimes I don't even care.
And these thoughts that I am useless and I am a loser and I WILL be a loser overcome me, and this leads also to a relapse
Also the thoughts that also come is that : I have nothing to replace with this pleasure, it is like the only thing I enjoy the most, and that's the problem.
And also I feel that if I will be in a commited relationship maybe because of my character my partener will not love , will not accept me, maybe she will break up with me, and this is based on a past experience of a relationship.
I am very curios about how you could succesfully quited it, because for me seems impossible and I really need to quit because I have a big exam this summer and all my future career is based on it.
I want to my mind to be clear 100% but it seems like I can't get rid of it forever, because I find pleasure in it , it is the only thing I enjoy the most.
All what I've done is that I've reduced the frequency from daily to weekly.
I don't want to live all the rest of my life with porn ;(((
And sorry for my bad english, but I really need help to break this chains forever