This.
if they want to act this way, let them…in the end it will be their problem. Dont make it yours. Even if its partially fake, be happy and confident, be good to them and especially yourself. This sounds stupid, but please try it. Anytime they do something rude like the milkshake thing, smile. Seriously, sit there and smile to yourself.
Because if you keep letting their behaviour affect you like this, it will ruin your relationship with your husband. TRY to find something out of the house you can be involved in, or take some online classes..anything!! And dont show them that their behaviour is affecting you in any way. Seriously, be more confident from now on, you derserve respect from them, and if they are unwilling to give it to you, then its their loss!