MAH NIGGA! I'm 20, 6'4" but I'm skinnier than you, 165lbs.

I was thinking in drinking 2 shakes per day consisting in milk + chocolate powder , 1 yogurt , 1 banana and 100gr of oats, it's about 1000 calories per shake, so 2000 calories. I need about 3000 per day, so the normal lunch and dinner would suffice, the thing is I cannot at the moment drink the shakes I'm doing, it gets a lot of foam and it tastes a lot bitter and a bit like acid, so I'll probably go as you are going, half a gallon a day of whole milk or something, which are like 1200 calories.

And with the addition of trying to eat the oats solid, with a banana and a yogurt, which is easier for me.

So, try to incorporate oats in your diet, since 100gr of oats are like 350 calories and if you eat two times a day it's almost 1/3 of the calories you should ingest at that weight.

So, half a gallon of milk per day plus 200gr of oats will give you almost 2000 calories.