Oh yes, been there, and done that so many times (both shoulders; pinched nerve in my back; broken leg; and dislocated knee) Like others, I would scream just trying to sit up to use the toily and DH had to help me also. During those times, I could hardly sleep or find a position that one could sleep in, so I half-situp on the couch: wrapped myself up well, and eventually would nod off from sheer exhaustion ... oh yah, and the sobbing and praying did help a bit too. Truly, you will get through this too!
Forget about the diet for now; just maintain for awhile -- you must focus on getting better. The last poster suggested many of the things I was going to. Have someone pick you up easy things to eat; honestly, I ate easy things like sandwiches, toast with peanut butter, and some things that I could eat with only my left hand (yes, I ordered in already cooked chicken). Premade salads are a GOD-SEND in these times; you can get Ziggy's or other brand Coleslaws, Potato & Pasta Salads (and they taste great). DH went and bought things that he could make that are easy like hot dogs & hamburgers: these can be done with one hand eventually.
The first week or so ... I ate what was "grab & eat" type foods; and I don't recall gaining much weight, if any. Buy already cooked meats, salads, and cheese; all easy to grab, becuz eating with a fork can be difficult in your opposite hand. Deli meats & pasta salads, peanut butter, granola bars, fruit, and stuff like that too. Today, you can even get pre-cooked bacon, hamburgers, and sausages that you just heat up in the microwave (these can be eaten with deli salads too). Our store has already made bags of salad; all you have to do is add dressing, and after awhile you can eat it with your opposite hand (I actually got good at it). Use a big spoon at first though ...
OH, and I just remembered that I could eventually eat with my right hand when I held the bowl up to my mouth with my left hand. Cups of soup would be handy during this time too ...
Hope you have some family and/or friends around that can help you during this tuff time ... prayers ascending for you as well!
PS ~ my DH just commented that it must have taken you hours to post with your left index finger! Yah, he's a hoot, isn't he? I'd smack him for ya, but that might be considered abuse!