Possible preeclampsia

Today I had a scan and they took my blood pressure (I'm just coming up to 29 weeks but have frequent scans due to the medication I'm on) and my blood pressure was slightly higher than usual, so they started to consider preeclampsia. They made sure I'd see my midwife in the next week to get it looked at again but the concept of possibly having preeclampsia after reading so many horror stories has really upset me and caused a lot of anxiety! Can someone please tell me a little more about it and try and calm me down a little? I'm only 19 and this is my first pregnancy so my anxiety is very high!

Thank you🌈