I used to have all different types of VP shunts until 2004 when coming out of a craniotomy I had a stroke & couldn't move one side of my body. Fortunately, I regained movement of everything in a day or so. Due to the risk I can no longer have shunts placed in my head. At the time I had both the VP and LP (lumbar) shunt. My VP shunt when it was working properly had me feeling great, however it blocked all the time & I would crash. Now having just the lumbar shunt, I don't have it blocking all the time, aside from a few infections it stays working good but I get bad headaches everyday.
Overdraining is some of the worst headaches I've had so I feel for you, and hope they can get your pressure set properly & get you feeling better. I remember when the programmable valves first came out and it's a blessing to so many. It replaces multiple surgeries to a procedure that takes 2 minutes to do and a couple x-rays.
They've come a very long way with the research & development of shunts. With hydrocephalus not being as popular as say cancer or other diseases, it lacks the financial support yet has still managed to improve the quality of life for patients. I wish you the best