If what you’re doing now is not moving you towards your goal, stop doing it!
Ie. Eat more, as Bull suggests, and drop the endless cardio.
For legs try doing just one or two tri-sets per week. For example, 6-8 squats, 8-12 leg press and up to 25 leg extenions or walking lunges. No rest in between sets. If done right you’ll end up with the most incredible lactic acid burn. The important thing is not what this type of training does or does not do but that it’s totally different from what you’re doing now. Use a tape measure to gauge progress.
Then devote the rest of you training time to the body parts you need to bring up.