I am so sorry you are going through this difficult situation. What happened is you have failed to take care of yourself. Remember the airplane scenario where you are to place the oxygen mask on yourself even before the little children. It is because if you do not put your own welfare first you are at risk of disabling yourself and if you can't take care of you, you can't take care of others. You must evict the roommate immediately. Also, call police and advise of elder abuse if your being intimidated or abused -taking advantage of an elder person may be elder abuse in your community. NEVER put up with late rent like that again. Never let others use your car if it is the only one you have, or if you ca not afford to be liable for what they do. You may be able to find a community legal service that helps elder persons for free to assist you with an eviction and collection of the money owed you.  Act right away. Call police if he gives you any indication he will harm you, even raising his voice at you. And, before renting your place out know how to evict. Commence the process right away when they are late. Also, get a security deposit.  You can stop eviction if they pay, but you cannot always collect back rent and it will accrue if you wait. So consider not tolerating any late payers.