At four weeks, you might only be able to eat 1 oz (on a good day). Forget about the amounts listed in the meal plans. They may be goals. I can barely eat 3 oz of deli turkey now, and I am almost 2 years out. Early on, I couldn't tolerate deli turkey. You might try things like tuna or softer foods, such as cottage cheese or yogurt. I couldn't eat a half cup of anything that early out. Go at your own pace and supplement with protein shakes, so that you can get your protein. Everyone moves at a different pace and has differences in tolerance.
Listen to your sleeve. I couldn't eat 3 ounces of protein until I was several months out. First, it was half an ounce, then one ounce, and gradually worked up to 2-2.5 ounces, when I was about 4-5 months out. Today, there are days that I can eat 3 ounces of dense protein and other days, I can only eat 2-2.5 ounces.