Anyone know anything about altitude sickness?

Hey all, my husband and I are on our honeymoon (3 years later haha). I've been feeling on/ off sick since we got to Montana.

Dizzy, fatigued, nauseas, headaches, heart palpitations and a little short of breath.

I'm currently 12 weeks pregnant. Today I feel terrible. Really out of it. Also, I am now projectile vomiting. I thought I felt so unwell due to lack of sleep since I've struggled to sleep since we got here.

For this pregnancy I've been having some nausea and a general feeling of unwellness. But since I got here its x10.

I was wondering if it might be altitude sickness? However, we're only at about 5200 feet. The state we are from is 289 feet.

Any thoughts? I just feel so sick and miserable 😔