See if you can find dry curd cottage cheese. It's pretty much pure protein. Some people find it alarming, as it's quite different from what comes to mind when one thinks "cottage cheese," but it's nice on salads and rolled into egg white omelettes.
I loved being out keto, the pounds really fell off. However it's advisable to keep switching things up to keep your body burning fat. For Psmf buy lean chicken and meat cuts, remove the skin off the chicken. I grill my meats instead of frying them in butter or lard, which I would do on Keto. I boil my eggs instead of having them fried.I eat a lot of fish, which is a very lean protein, I tend to grill it or pan fry it with a little olive oil. Use an oil spray instead of olive oil or butter.