I currently don't have legal status in the US, I overstayed my visa. I am now trying to collect money my ex boyfriend owes me for rent on an apartment we shared, we both signed a 1 year lease, he was at first willing to pay his half but has now apparently changed his mind.

I was told to file a lawsuit against him to force him to pay his share but I am not sure if I can do that because of my immigration status. Do they even care about my status?

Thank you.

Yes you can file a lawsuit, the court will treat it like any other case. However win or lose there is always the possibility that the court will advise immigration authorities of your expired visa.