Need advice as a renter

[Robert Ferrell]

Hey everyone, this is the situation I'm facing right now. For the past 15 years my mother and I have lived in one unit of a duplex. Weve been excellent tenants and have always paid rent on time. Recently, the owner of the buliding sold to our neighbors in the back half of the duplex. This neighbor gave a verbal agreement to us that he would not make any changes and always be willing to work with us because he knows our situation (my mother is on permanent disability and section 8) and also because he knows we're good and reliable people. 

Now, about 3 months into him being the new owner he has brought up some issues about how "unfair" it is that we pay such little rent, a number that he knew well before purchasing the property and a number he well knew when he offered his verbal agreement, granted, it is pretty far below market. This is mostly because he got himself into an extremely bad deal and pays a ridiculous mortgage. And is now demanding a $200 increase in rent or possibly less with exceptions such as we will no longer have use of the driveway or front yard or side yard storage. 

I understand we have been lucky with owners in the past and our rent not being increased too drastically over the time we have been here, but is there anything we can do to counter this? Does the verbal agreement mean anything? And can a landlord restrict certain areas off from use like he has proposed?

Any suggestions or info would be greatly appriciated. We really dont want to have to move, mostly because moving costs alone would be nearly impossible, not to mention a first and last months deposit on any new place. So any advice will help. Thanks.