I know this story well. In some ways, you are lucky. Ectomorphs usually do well staying lean while making gains and don't have to work as hard to get lean when they diet down. But yes, the hard part is gaining muscle. I'm not going to lie. An extomorph is going to have to eat a lot more than his meso or endo counterparts. The good news is, it is very rare that someone is a true ecto. There are usually some latent tendencies toward endo or meso, that you have not tapped into yet. The key is going to be finding what you need to do to make the most of the genetics you have. 

This is probably going to come down to eating more. At your height, even if you were a true ecto, I believe you can hold a lot more muscle, naturally. You're in the right track. You want to find out how to make yourself grow, BEFORE you start using gear. Nothing is a bigger let down than gaining all sorts of mass on cycle, only to see it go away, shortly after you stop the gear. So start by making sure you are getting about 350g protein a day and start adding carbs on top of that.

Word of advice, There is a chance you will gain some fluid within a few wks. Skinny guys often think they are getting fat after bulking for a little while. So many times, they abandoned their bulking program or cut it back out of fear. I'm not saying you have to get fat to main muscle, but you can't look awesome when you are trying to do some major construction. Follow through. And remember, just because the program works at first doesn't mean it will continue to work through the entire bulk. As you get bigger, the diet will NEED to change for you to accommodate your added mass

For you or anyone interested, I am accepting clients. Getting guys big and ripped, helping them acheive their goals, quickly and effectively, with individualized programs : Next Level Nutritional Services