Your common 'non-solid' high-protein items are:
- peanut butter, or other nut butters
- cheese (cream cheese or served melted)
Depending on how strict you're being with the fat intake, you can go even further ... low fat or non-fat yogurts and cheese (eg. neufchâtel instead of cream cheese); whites only for the eggs, etc. Be warned that if you try to go too low-fat during this time, your body might actually crave more feed, making the problem worse. If it's not a problem with your body being unable to process fats, you might want to reduce protein but increase fats during this time.
The good news is that unless you're a body builder, having a lower protein diet for a week or two while things heal won't cause your body to start eating itself -- in fact, most American diets have more protein in it than our bodies need -- about 3-5oz of meat per day (not per meal) is enough; exact amount depends on your size and build.
As you can get away with soft foods, and not just non-solid:
- Scrambled eggs (leave out a few yolks if you're really sensitive to the fat).
- Pulled pork, roja vieja, pot roast cooked 'ragout', or similar (you might need to also chop it up if the bits of meat are long).
- Pasta with an egg sauce (like carbonara, but might have to avoid the black pepper and/or crispy meat ... might be able to use a soft ham and/or add extra salt or worcestershire) or a cheese sauce (eg, macaroni and cheese, alfredo)
- Tuna fish (canned in water; can either make into a tuna salad (avoid celery. Use a grater to extract onion juice for flavor without solid bits of onion. Pickle brine can help brighten it up while being non-solid)
- Refried beans (make your own, and you can cut down the fat significantly)
- Many soups. (either make a strong stock, cook the meat 'til it's soft, or put it through a blender ... or egg drop soup)
- Cheesecake (use neufchâtel cheese, or find a recipe that uses soft tofu)
- Flan, custards, or ice cream (made with a custard base, but low-fat milk)
You can also work some extra protein into other dishes ... thin your mashed potatoes with (pre-heated) stock a bit more than you typically would, then while still hot, blend in a egg or two. Or add neufchâtel cheese instead of milk or butter (add stock if you still need to thin it further for your tastes)