I would also go back to the Blood Type Diet . Some of these foods you're doing well with are ok on that diet. Bananas are a clue, since you can't tolerate a drop of Sugar yet bananas are working out.
So go down the Blood Type Diet list one by one and see how they work out, perhaps pineapple will be ok too. I think keeping a journal for a few months would help.
I like the idea posted above of amino acid supplements. You can try a good quality whey, rice, or pea protein source. Look also for hydrolyzed protein sources since these are essentially pre-digested.
I would definitely add ginger into your diet as tea, or juice or any way you can get it. And of course it would not be a proper post by me if I didn't mention strong lipton black tea boiled down 2:1. 3 bags tea and 4 cups water boiled down to 2 cups.
In point of fact O's do not necessarily need 'quite some' meat, according to the books you need a small portion the size of your palm. I would try organic filet mignon extremely rare, almost raw, see how that goes if you're craving protein.
Look into a high quality bovine gelatine, or make your own from cartilege/bone broths.
Fats are what will solve your feeling of starvation.
If you can afford it get only grass fed red meat and butter.
Also try super spicing your next attempt at meat, maybe white meat chicken will be ok, and add in heaps of ginger, garlic, cayenne, and any spices you find appealing.
There is definitely path out of this, but you need to keep trying things and don't rule anything out until you actually experience it.