What is your social limit with friendships?

I was just wondering what you personally think your limit is with hanging out with friends each week. Personally, I feel like hanging out once or twice a week is enough for me but I have this friend who hits me up to hang out every day almost and it’s tiresome. I do say no when I really don’t want to but I feel bad. We hung out like 3 days in a row for a couple hours each, and today she messaged me twice asking what I’m doing today, I said I was busy the first time, she said okay. Then DMs me saying she misses me and she wants me to go to her house to do the work I need to finish. Had to once again say no. I have a lot going on, working 2 jobs, full time student and I’m in a relationship. What is your boundary with friendships?