These are two separate transactions (the loan and rental agreement), I would need to know all the terms of the loan and the terms of the rental agreement. If you are in breach of the rental agreement, he can evict you. If you are not in breach, then you can go to court and fight that. If he owes you money on a loan, you can sue him for that money. If the amount in dispute is $7,500 or less, then you can sue in small claims in California. Otherwise you may need to go to court.
This communication does not create an attorney-client relationship. A full review of your case, including actual documents and consultation is needed to render proper legal advice. Please consult an attorney before you decide on a course of action.
Investment advisors are heavily regulated both on the State and Federal levels. I don't know if it is in your favor to connect the rental of your premises from the landlord with this loan/investment loss that the landlord accepted. I'm a bit unclear if the landlord is repaying you or if you are renting, from your description. You may want to consult with a lawyer who handles securities to review the papers you have. If this is an illegal investment, perhaps you can get all of that money back. The issue of your rent, at least in my mind, is separate if you have an actual tenancy agreement. It's confusing if they are combined into the same case. If you are planning to sue this person, you may wan to live elsewhere, as landlords have a way of doing nasty things when they are angry at the tenant and this lawsuit would become a sour point.