What are your goals exactly? Current diet/training etc?

Hey man thanks for joining the group, good to have you. Here's some basic pointers that have helped me put on some lean mass: Cut out the cardio! P90X is a great program, esp for shredding and endurance, but not great for building mass especially if your calories arn't very high. Take breaks more often (1-2 days off a week) and bigger breaks once in a while as you stated you will (1 week) Lift heavy, with ample rest time (Lift 8-12 reps, rest 2-3 minutes), definitely switch that up, but use that kind of schedule during your mass gaining phazes.

Diet: We need to know where you're starting (body fat, weight ect)
-But generally I've found that I need lots of carbs in addition to protein and fats (I'm 149 pounds, and shoot for about 3,000 cals a day)

Well my weight last checked was 199 lbs. Body fat is 8.5 to 9
I am eating around 3120 cals a day and making up the Cals I burn off working out.
Carbs 50%, Protein 25%, Fat 25%

I'd run macros closer to 40/40/20. To pack on weight (note I have a pretty high metabolism) I had to eat ~600g carbs daily and was shooting form ~300g protein. If you're burning off everything you eat you're gonna need to eat more. Maintaining muscle takes up a lot of calories, building it chews up even more. Shoot for ~3-500 cals above maintenance as a starting point, gotta eat big to get big.

P90x is great for cardio/endurance/toning, you get what you put into it, but it's horrible for gaining muscle. From your #'s you seem pretty solid, I'd up the protein a bit and hit the weights hard. I've had the best luck doing lean bulks eating like I said above, and starting my routine with heavy compound movements 6-8 reps (2 reps short of good failure) and finishing with higher rep stuff 15-30 reps (to failure) to really get the muscle bellies full of blood.

Well my weight last checked was 199 lbs. Body fat is 8.5 to 9
I am eating around 3120 cals a day and making up the Cals I burn off working out.
Carbs 50%, Protein 25%, Fat 25%

I'd run macros closer to 40/40/20. To pack on weight (note I have a pretty high metabolism) I had to eat ~600g carbs daily and was shooting form ~300g protein. If you're burning off everything you eat you're gonna need to eat more. Maintaining muscle takes up a lot of calories, building it chews up even more. Shoot for ~3-500 cals above maintenance as a starting point, gotta eat big to get big.

P90x is great for cardio/endurance/toning, you get what you put into it, but it's horrible for gaining muscle. From your #'s you seem pretty solid, I'd up the protein a bit and hit the weights hard. I've had the best luck doing lean bulks eating like I said above, and starting my routine with heavy compound movements 6-8 reps (2 reps short of good failure) and finishing with higher rep stuff 15-30 reps (to failure) to really get the muscle bellies full of blood.

What he said to a "T" well put man! "gotta eat big to get big" <- solid advice right there.