I hear this statement all the time - "can't gain weight no matter how much I eat" You have to realize that you are not the only one having this problem.
You are most likely an ectomorph.
An ectomorph is someone who has a very fast metabolism, long limbs, and a skinny figure.
You can't change the hand that you are dealt.
Not everyone is born to be genetically blessed.
When you say you are eating too much, you have to realize that is just an opinion.
How do you really know you are eating too much? Your body might be burning 2,000 calories per day, and if you are eating 2,000 calories or less per day, then there is no way that you will build muscles or gain weight.
You need to have a surplus in order for you to gain weight.
A lot of people say they do not have an appetite to eat more than what they can handle right now.
An easy way to solve that problem is to add tiny little bit more to every one of your meals.
I'm not saying you need to DOUBLE the portion.
You start off with little bit to the point when you don't even notice the difference, and your body will begin to get used to eating more.
Gradually increase your portions.
Weightlifting will also help you gain weight from building muscles.
Stick to exercises that focus on multiple muscles at once, such as, deadlift, squat, and bench press.
Do not waste your time on bicep curls because that will only help very little to gain weight or build muscles.