Tell us what these physical problems are- why can’t you deadlift? Maybe you should just do bodyweight stuff until you get some decent level of development. They have these rotating push up things that are very good- get them. Work the bodyweight stuff until such a time as you can progress to actual weights.
You look to have a small bone structure so don’t expect miracles here. You don’t look particularly short, so you have your work cut out for you.
I don’t know what the deal with the juice is- why they say not to drink it escapes me. In any case, yeah you need to eat but unless you’re looking to be dialed-in as far as definition and al the rest then you really don’t need to stress the exact proportions of this or that in order to get size on. I don’t watch what I eat as far as protein and carbs (I don’t eat stuff that is high fat, though- but I’m not afraid of a salami sandwich here and there) and I just did my routines and went from 190 to 207 in about 2 months with no increase in the waistline but with great gains in strength and muscularity.
I couldn’t tell you how much protein I had in a day for the past 6 months or more and it hasn’t affected me in any noticable way. Unless you’re trying to go competitive I think diet is stressed way too much. Sure, you’re an ecto but the solution is never to force feed yourself- the real solution is to gain 5-10lbs over a few months and then maintain your new weight for over 6 months.
Once you are able to maintain that new weight you will see your body holds onto it and it becomes your new natural bodyweight (for most). Then, and only then, eat more until you gain another 5-10 lbs. Repeat the aforementioned procedure, and in a year you should have added a decent, non-illusory-non-fat/water-weight amount of weight (10-20lbs) and size that you won’t have to worry about disappearing as soon as you stop chewing that last mouthful of food.
So, what is this physical problem of yours?