Copying a response to one of your previous questions, because it's equally relevant here:
Let's look at your numbers. You've previously stated that you're
60-63kg, can do 12 pull-ups, a 1RM squat of 100kg, deadlift 120kg for
5 reps, and have a max bench of 65kg. So you can squat over 1.5 times
bodyweight, probably deadlift in the order of 2.4 times bodyweight,
and can bench just over your bodyweight. Those are not bad numbers, at
all. Far better than most people will ever achieve in their entire
lives.
Since then you've increased your bodyweight to 69kg, and now describe yourself as having "a full flab". So is the extra weight you've gained all fat, or have you been getting stronger as well?
Either way, if you're gaining significant fat, it's because you're eating too much, so the solution definitely isn't to try to increase the amount of food you're eating or the energy you're absorbing from that food.
And if you aren't gaining muscle or strength, then that indicates any one or more of:
- Your training is inadequate to promote additional muscle growth.
- You're not getting enough sleep.
- You're not consuming enough protein. (This is unlikely to be the case.)
- You've just gotten so close to the maximum amount of muscle that you could possibly gain that any further gains are happening too slowly to be noticeable.
Given that your lifts are quite strong relative to your bodyweight, and you have a reasonably high BMI, you are definitely at least getting close to reaching your maximum muscle potential. What you should be asking yourself, probably with the assistance of a therapist, is why aren't you happy with the gains you've made? (And if you're having suicidal ideation, as you're implying, definitely see a therapist.)