Beer is your friend.
Sounds like you have a full plate but remember Isaiah 43:2-3 which says “When you pass through the waters, I will be with you; and through the rivers, they shall not overflow you: when you walk through the fire, you shall not be burned; neither shall the flame kindle upon you.”
Don’t take responsibility upon yourself for things you didn’t do. You didn’t choose to become sick; you didn’t choose how your grandfather wrote his will; you didn’t choose for your friend to take drugs - so don’t compound these problems with guilt.
Continue to seek professional medical help for your illness. Don’t take sides in the family dispute but remain in contact with both sides. Remain in contact with your friend - don’t assist him directly or indirectly in his drug use but continue to be his friend if you can. If you can’t find a job, volunteer work is a good idea - it can help you feel better about yourself, it keeps you in the routine of working, it helps keep your resume full, it can help you network which might lead to a job, and obviously it helps other people.
Finally, as somebody else said, remember that your church is a community. If you need some help right now, seek it out and accept what they can offer you. In the future, you may be in a position to help others out in return.