If you are truly trying to gain (or cut) you need to track your macros. Some people will argue against this, but if you're not making progress (getting bigger, leaner, what ever your goal is) then you need to start tracking. I would get an app or go online and find the nutrition info of what you eat in a normal day so you can breakdown your macros (and thus calories). Then adjust according to your goals. There are tons of macro splits out there, so you're going to have to experiment a little to find out what best suits your body. And don't worry so much about missing breakfast, a lot of guys make great progress with intermittent fasting. Hell, I've even made good progress at times with the warrior diet (fasting 20 hours, eating 4)!