I saw that you posted some excercises (hip flexors etc) hurt your back or something, you need to strengthen your lower back and core thats probably why your having trouble getting rid of that extra fat, chillen will probably be able to advise you the best, but I would say add some proper deadlifts. I use to have trouble doin certain ab workouts and then I was introduced to planks and that helped me alot and it also helped me with my abs. make sure you do all kind, using a swiss ball slide on the balluntil your kness are relaxing on it and then work in and out trust me you'll feel the differnce hope that helps.