Maybe I worry too much, but I want to know how caregiving will affect my overall health.?

Up to you. Caregiving can be very rewarding and can enhance your overall health when you come from a place of love. Caring for a newborn can be tiring but is an amazing experience. Caring for an aging ill parent can be very stressful and the opposite kind of experience. Know your limits. Ask for help. Be sure you take care of yourself so you have the energy to provide care. Eat well, drink plenty of fluids.
More. Get outside. Studies show that caregiving can have an adverse affect on one's overall health when the caregiver is sandwiched and stressed....So #1 is finding ways to take care of you!