IF schedule

I have been eating on a 7 hr frame. 11:00 med plain sweet potato and 4 oz chicken, 6:00 a veggie salad with 4 ozs chicken and oil and vinager homeade dressing. I lost 7 pounds fast within the first week. This second week I lost 1 then gained 1/2 back. Should I do away with the potato and stick to salad? Do I only need 2 meals in the time frame? Should I cut to 6 hours? I really want to do this right. I have indulged in a diet rite once a day because it’s caffeine free and sodium free. Should I not drink those? I do drink lots and lots of water.