As long as there's a split, that split is going to keep splitting further and further up the hair shaft. And the only way to get rid of a split is to cut it off. Tell your professional hair cutter to give you a cut a short enough to cut away all the splits, even it that means shaving your head.
In the future, get your hair ends freshened every 4-8 weeks. Freshen means trim away all the old damaged ends, like trimming away about 1/4 inch (6mm). Your hair grows about 1/2 an inch each month, so your hair will still be getting longer -- just not as fast. Long hair looks like hell if it's split and scraggly, so shorter healthy looking hair will always be a better choice than long poorly cared for hair.