Overbearing and controlling parents

After my fiancé passed my parents thought it would be a good idea to move in with them. It WAS a really good idea. I was struggling mentally and was in a very dark spot. so being back with my parents and one of my siblings was absolutely the best choice. It also was meant to help me straighten up my finances. I am still living there. Things have been getting better for me. I am doing better financially as well as mentally. I’m work full time and in grad school and have a guy I’m seeing regularly. My problem is that my parents have started being completely overbearing. They are treating me like I’m 16 again. They tell me I’m not allowed to spend the night at his house, always wanting to know what time I’ll be home, wanting me to call, text when I get places, questioning where I’m going, who I’m with. They're constantly nagging me to stay on top of my school work. I seriously had looser reigns on me when I was a senior in high school. How do I tell them I’m an adult, I’m handling my job and my school work and I’m fine to go out with my friends and have a relationship if I want one? I help with household chores and cooking. I’ve also offered to pay rent but they’ve refused that because they want me to get my finances back on track and save up as much money as I can. I know the obvious answer is to move out. that is my ultimate plan but won’t be happening until summertime next year. How can I respectfully tell them to back off? I’ve tried but it always turns into a fight of some kind and I’m tired of it. Feeling really beat down after a crummy weekend.