I’m training a client right now that is very close to your size that is also struggling to gain weight. He is taller and just a bit heavier, but is around 9% BF and is an ectomorph, just like you.
#1, From what I am reading, you are not eating any where near enough calories!!! Period!!! I think you might be worrying to much about the numbers and/or fat gain. With your metabolism, you can strip off excess fat in a matter of weeks, so that should not be a concern. In fact, getting your BF up a bit would likely help make a better anabolic environment.
#2, Your carbs are WAY too low! I would get 350-400 grams of carbs a day. Minimum!
#3, Your protein is borderline too high! It takes roughly 25-30% of the calories in the protein you are consuming to metabolize it. Therefore, 100 grams of protein is actually closer to about 300+/- calories, not 400 cals like one would think. You are in a sense eating too many “negative” cals from protein. 1.2-1.5 X LBM in grams is usually plenty for bulking. Hence, 200 grams a day is plenty for you, 50-60 grams PWO in a whey hydrolistate/isolate is very important. The rest of the day you want slow digesting proteins from beef, chicken, eggs, and casein.
#4, Carbs should actually be the focus macronutrient when bulking. This is a big mistake many novice trainees make all too often, especially ectomorphs. You have got to get more carbs from whole grains, but even pasta and bagels are fine since you have no fat gain worries.
#5, After slightly decreasing protein and greatly increasing carbs for a few weeks, check your weight. If you are gaining you are doing something correctly. If you are still maintaining, increase your healthy fats ON TOP of the same carbs and protein intake. Eat gobs of peanut butter, cook with 3-4 table spoons of olive oil, and pour on the salad dressings.
#6 and 7, Eat a HUGE breakfast and a rather large slow digesting protein/fat meal before bed.
#8, If you are STILL a skinny dude after doing them for a month, schedule surgery to get that tape-worm removed! LOL!