Catholics: Should I give up?

I have been praying for so long to God and I have finally given up my homosexual acts. I still try to find boyfriends, but God has helped me to be chaste. My problem I am facing now is pornography and masturbation. I confessed it last Saturday and all week I was tempted to do it and I resisted it, but tonight I ended up doing it again. I feel like I am always going to be a failure with it and that I will never overcome it. I am so scared of going to hell in mortal sin. I am going to confess tomorrow most likely, but I still feel like even though I confess it isn't sincere enough since I fell into doing it again. Should I just give up? All this week I kept being tempted by it. It only happens at night time though as I am unwinding. I feel so horrible now for giving in. Is this something that will be cured overnight? I keep praying, but I just worry I am a failure...