Landlord Locked us out with written notice

We have a month to month agreement with a landlord. We were going to open a restaurant in the space, but we lack the funds to get it going. He agreed to let us stay in the space until we found another investor but that's not going to happen. Earlier when we were in the space, he gave us permission to modify some of it. He even helped us determine what walls weren't structural and told us what we could remove. So we removed 3-4 sections of walls connected some smaller rooms. In lease negotiations we were going to rent all 3 rooms instead of one. We ended up getting 2 months behind in payments, so I understand his want to evict us. But he changed the locks on us and sent us a text that said he was going to hold our equipment or seize it as collateral until we agreed to pay him back for the damages. We never signed a lease. We never got a proper written notice. He clearly wants us out, but won't let us leave. I tried to get stuff out and he won't unlock it for me and threatened to sue me.