Learn how to shoot into your other veins. When I was new to injecting drugs, I had the same problem, and never bothered to try and shoot into another vein until I could no longer register, so I started to teach myself how to switch it up. A lot of people go in at too steep of an angle so they can't hit the veins lower down on there arms or around the wrist, these veins are also less tube shaped, and more flattened, so you have to take that into account, as well as the fact that they tend to roll. I always would approach these "rollers" by sort of spearing them, by which I mean injecting at a shallow angle in the direction that I visualize them rolling towards. Just practice with some fresh works and sterile water. I can also almost guarantee that if you give that one vein a break for a few weeks, it'll heal itself. If anything it's probably thrombosis, which isn't great at all but it can probably come back with some time.