Dentist office said that I need deep cleaning, is it worth getting a second opinion?

TLDR; Dentist office that felt scammy said I need a deep cleaning but I can't afford it, even with HSA card. Is there anything I can do at home to help with my teeth? Should I get a second opinion in a month and a half?

I went to the dentist a month ago and got an exam, where they said that I needed a deep cleaning. It has been years since I've gone and I figured my teeth weren't great. They said I didn't appear to have cavities but the deep cleaning alone would cost $3000 out of pocket. I can't afford that and they just walked me out of the office. I made an appointment for tomorrow at a dentistry school, but I have $30 in my bank account to get me to my paycheck next week and I can't afford to drive all the way to the school and back and also go to work.

I have dental insurance and an HSA card, so I thought maybe I could make an appointment closer to my university in august. Is it better to wait and try again then? If so, how can I take care of my teeth until then so I don't make the problem worse? ty for any help.