I live in Southern California so I am not sure what the law is in the Midwest, where the OP lives.
But here, unfortunately, unless you are on a lease, it's perfectly legal for a landlord to raise the rent as much as they want.
The landlord only has to give you 2 months' notice of the increase. There is really no limit on how much they can raise it.
I looked into the legalities because my rent was raised
$250 last October. It literally caused almost all of my hair to fall out from the stress. I was barely making ends meet before, and now I go into debt every month just because the landlord is greedy.
I am on a month-to-month tenancy, so I don't have any rights. It's hard work being poor! I hate it. It's even worse trying to provide enough documentation to get food stamps and Medi-Cal. Ugh.
I feel for you, I really do. But we are stuck. There are no rights for renters anymore.