Thanks, Starguard. I went by ambulance to the hospital immediately after the accident. At first, it felt like both my knees and my right hand were broken. They did an MRI of my head and neck and x-rayed my chest, pelvis, legs, and hand. Diagnoses: head injury, cervical strain, chest wall contusion, abdominal wall abrasion, abrasion of chest wall, hand contusion, knee contusion, lower leg contusion. Doesn't mention the seatbelt rash on my neck and clavicle area, or the air bag burn on my hand, wrist, and arm. Doesn't mention the pulled muscles in my neck, the scrape on my forehead, the scratch on my chin, and the red mark across my cheek. However, although I may have whiplash, I think I'll live. Could have been so much worse.
Walked down and looked at the accident site today. The tree fared better than I thought. A big circle of bark was knocked off but it looks okay otherwise. Some large, decorative rocks were dislodged from the flowerbed encircling the base of the tree and there is some deep rutting in the ground from the tires, but those look they will recover. From the tire tracks, it looks like I barely missed being shoved into the corner of the house before being shoved into the tree. Those tire tracks may have been from his truck and he stopped just before hitting the house while I was shoved off somewhat to the side into the tree in front of the house.