I used to have a 1 year extension visa based on marriage, but due to not being able to deposit the 400k this year, I had to switch to a multiple entry visa where I have to leave the country and come back every 90 days.

Now, my current address reporting paper in my passport, which I did while I was still on the 1 year extension, is expiring next week. But I'm not due to leave the country for another 90 days stamp until in 2 weeks.

Do I still need to do the address reporting now? Or does it already count as address reporting when I came into Thailand 2 1/2 months ago?

Your last arrival about 75 days ago reset the 90-day clock. Only if you now stay longer than 90 days counting from that arrival date will you have to do a 90-day report again. If I have understood you correctly your last arrival was with a multiple-entry non-O visa which means that unless you overstay you will never stay in Thailand longer than 90 days at a time and you can remove that old receipt from your passport.