Pressure Issues

Hi all! I am 6 weeks post-op from a PFD and yesterday I went to a BBQ at my parents home and they live an hour away and up into the mountains from where I live. So there were multiple elevation changes on the drive up there. At the first significant change, my head began to feel as if it were caving in and I lost the ability to speak and tears began rolling down my face. It was in no way painful, just a ton of pressure! I also had the pressure in my throat, neck and chest at the first elevation change, but I think that was panic because I was so sure I had made a huge error in attempting to make this drive so soon after surgery. My boyfriend asked if I wanted to turn around and go home but the BBQ we were going to was for my birthday and a lot of people were coming plus I felt if I just kept going up in altitude the pressure in my head would balance out, which it did. The first instance was the worst because I was not prepared and I felt like it would not end and I had done something wrong. It happened to the same degree 5 more times on the drive, 2 of them taking my vision during the course of the pressure change. All would subside as soon as we would reach a higher altitude. After I reached my parents home, I felt crappy for about 45 min then was fine for the day. And it did not occur on the drive home. I thought I would run this by you guys and see if anyone had any thoughts as to why this happened or if it's just one of those things. Added note, two weeks ago I had a fall and got a bad concussion (yes after surgery) so not sure if this is part of it. Thanks for any ideas or input you can offer!

I haven't noticed too much trouble with elevation changes so I'm not much help there. I live in WV so I think I'm already at a pretty high elevation and haven't traveled anywhere higher recently. I do however seem to have pretty bad head issues when storms are on the horizon. I'm 7 mos. post op.