Heightened Anxiety

A little background..So back in 2014 I had a panic attack out of the blue. I was home on a Saturday afternoon with my two girls and bam, I thought I was having a heart attack! My brother who lives a couple houses down from me and is a police officer, came rushing in and called 911. He was off duty that day. The paramedics took one look at me and said classic panic attack. After talking to my primary a week later, I decided that I didn't want meds or anything. Fast forward to that June and I was back at her office asking for help after having weird anxiety episodes. I was put on Lexapro 10mg and did pretty well with it. 
When I found out I was pregnant, I weaned off immediately. I've been ok since then but lately have been experiencing increased anxiety, mostly about my health. For example, I felt great today and was sitting on my couch with my husband and kids after dinner and I suddenly felt like I couldn't catch my breath. My heart rate starts to pump and I get that rush of adrenaline. It sucks so badly. I should say I'm healthy. I have great blood pressure and no problems with this pregnancy, thank God. I take a half or a quarter of a Xanax if I really need to. I'll be 36 weeks on Sunday. 
Anyone else experiencing the increased anxiety?