If you have IJV compression, you will need surgery to allow your IJVs to reopen so normal blood flow can occur out of your brain. The doctor who said what your scans show is normal is clearly not familiar w/ what normal anatomy looks like in that part of your neck. An IJV should never have an area that is “flat”.
Extremely thick & long styloids sounds pretty awful. We will be interested in seeing your scans if you’re able to make 3D renderings of them. If you Google CT scan 3D slicer software, links for some you can use free of charge will come up. A number of our members here have created their own 3D images, so if you get stuck, send out an SOS, & I’m sure someone (not me, not computer savvy here 
) will com to your rescue from our forum.