Since it's commencement weekend you'll be hard pressed to find anything available around Bloomington. With the families of some 10k+ graduates coming to town, things book up so far in advance that most hotels have to use a lottery system for awarding rooms. And families are happy to pay the exorbitant prices since the baby is graduating and all that jazz

A few places you might try:

The Abe Martin Lodge in the Brown Couty State Park. It's between Bloomington and Nashville and per their online reservation site, they have a 1 bedroom rustic cabin available for $80 and some change. https://abemartinlodge.dnr.state.in.us/

The Spring Mill Inn in the Spring Mill State Park is about 40 minutes south of Bloomington. Their online reservation system shows a few different types of rooms available for anywhere from $94-$114. https://springmillinn.dnr.state.in.us/

The Scenic View Lodge. It's on 446 south of Bloomington and near Lake Monroe. You can call them at 812.340.4371 or 812.340.1712 to check availablility and rates.

These places may not be what you're looking for, but they're the options I can come up with on short notice.

Hope you're able to find something that works for you.