I have recently realized i have anorexia and i will admit it at this point but i am scared to gain weight i?

only weight 90 pounds and i know deep down i would look better if i gained weight but im not sure how to do this..me and my mom fight about eating constantly and it has overtaken our lives i want to fix it and i need advice on what to eat at meals snacks everything my mom says i should drink milkshakes, eat grilled cheeses stuff like that and lift weights no cardio is this right?