Struggling with lust/Need counsel.

So as the title says Ive been struggling with lust as a female ever since 13 and its like i feel so far from God and that hes given up on me. A point ago I used to engage in reading smut/ watching porn frequently that it became hard to stop. I used to just think that afterwards if i repent id be okay but i realize thats not true repentance because is rinse and repeat daily. Ive been convicted of that and have been trying to stop which has been semi successful but it just feels so hard as a young adult to continue to serve God and keep my faith in him because of this. I know its wrong to keep engaging and when I try to do right I fall short. Ive even started wondering if i have some sort of demon or evil spirit attached to me or is this a battle of my flesh. How do I die to my flesh and become better? How do i kill this desire to do my own thing?