Hello!
I suggest you to look after yourself. To eat well and exercise. Try to eat a high protein diet with cheese, egg, cottage cheese, milk chicken, fish and less carbohydrates such as bread, rice, cookies, spaghetti, desserts. What knee problem do you have? If you can't do gym exercise you can try swimming. Exercise of every kind will improve your physical and mental health too. It releases serotonine which is the hormone of happiness. At the beginning may be you will find it difficult to exercise but if you do it right and stay focused you will begin to love it. It will help in lowering your blood pressure too.
Best regards.