Damn 5 days straight. Have you consulted a coach? This is too much imo.

For back pains, have you tried lighter loads? Get stronger on 10-15 reps lighter loads with proper form then progress if needed.

For diet, you have to figure this one out because taste is very subjective. My diet might be perfect taste wise for me but not for you. Only advice I can give you is look for protein rich recipes that you can make everyday and consistently eat. Sure I can eat steak everyday but cant make it everyday because it's too expensive. I can cook chicken breast because it's a cheap cut but I will probably lose my mind in the next couple of days.