Hair is just dead cells. There is nothing that will keep what is outside of the follicles “healthy”. To assist in preserving it, wash it no more than necessary, use a gentle cleanser and conditioner, avoid heated items (rollers, dryers, curling irons, straighteners), and chemical treatments. A better chance of producing “healthy” comes from within the body: Plenty of rest, exercise, water, and a well-balanced diet. Are you taking any medications? If so, they can impact follicle growth. Another factor is hereditary, which we have no control over. Some medications can impact hair growth negatively or positively. As for cutting your hair, if you aren’t happy with it’s length/condition now, why not? It will grow back.