Air carrier Flight Attendant reported the aircraft had a second pressurization malfunction during the flight. Flight Attendant experienced physiological symptoms that rendered them unable to perform all duties after landing.

Narrative

Flight experienced its second pressurization event after originally diverting to ZZZ1. Cabin crew detected the same issues of pressure change in the cabin but the effects felt physiologically worse. The ear pressure and chest tightness became more and more noticeable as I continued with my duties and took a toll on my mind clarity. Upon descent; the cabin was preparing for a cautionary landing once again as we diverted to ZZZ. My safety compliance did not include picking up the plastic service items in my first class as my priority became to sit down in my jump seat after walking through the cabin and checking on customers using oxygen as my chest became tighter and tighter. The crew was finishing speaking to the Physician in command that had been contacted for passengers that were using oxygen for complaints of chest tightness. I walked through assured the cabin if anybody had any medical concerns to please contact us by alerting us with the flight attendant call button. I as FA1 repeated our prepare for landing instructions over the PA and made them aware we would be landing soon. My compliance checks were modified as I remained in my seat and my crew made their way thru the cabin. I instructed them to prepare for a cautionary landing and that sitting in our jumpseats was priority as we made our way into our descent.Upon landing the aircraft took longer to depressurize as we touched down and made our way down the runway. The entire aircraft shaked roughly for approximately 20 seconds on the way to a stop. I detected the difference in landing and called the aft galley to tell them something felt off with the landing and depressurization and to be careful of the doors in case we were still pressurized. After the call I felt extremely nauseous and head felt tight and achy. As I started to feel dizzy starting at the forward closet I felt vomit rising and made my way to the forward lav and left my jumpseat to relief myself. My FA3 remained in their jumpseat. I was able to come back to my jumpseat approximately 5 min after and remained unbuckled in case I needed to return to the restroom. I was able to disarm my door but my FA3 completed PA's for me and the crew disarming. During deplaning I was unable to remain at the door entry as I returned to the restroom to vomit. I was assisted by paramedics that met the flight and followed up care by ambulance and emergency room visit after the aircraft deplaned.Suggestions: Not use an aircraft that was and continued to malfunction. Have written procedures for what to do if FA is sick and away from jumpseat upon arrival; taxi; and deplaning.