I have a beautiful philodendron that is more than 15 years old
I have taken several starts from it and it still thrives. Lately I've noticed the ends of the leaves are fraying. I only noticed this because it's never happened before. I've also noticed small brown circles, like an insect's been munching on it. As of late, my plant doesn't seem to be doing too well. Please help.
Also (thought of this after I answered)....repot the plant but before you do, wash all old soil off the roots. My friend had a spathephillum (Peace lily) that was barely growing. The problem was in the soil: the vermiculite had gathered at the roots, preventing the plant from growing. Once removed, washed and repotted, the 'spath' began growing and is now a very impressive specimen.
It sounds like your philondedron is exhausted. Try rooting cuttings in water and create a new plant. I know that sounds painful but sometimes it is just the only thing to do.