In Parshas Nitzavim 29:18 the Ramban quotes the Gemara in Sukka 52 and explains as follows in regard to going after ones negative desires. The more you “eat” the hungrier you get. The Gemara says “Masbiyo Raeiv, mar’eevo soveya” which means satisfying your hunger will make you hungrier, and starving your “hunger” will keep you full(satisfied).The Ramban goes on to explain that giving in to your desires will eventually lead you to desire that which you never desired before. Unfortunately I have seen firsthand that this is 100% true- not that the Ramban needs me to vouch for his words.
HOWEVER, nobody should ever write themselves off as hopeless because one definitely can overcome it no matter if you slipped a few times. Hashem doesn’t ask us for the impossible.