I have had the same issue recurring times. I often get them when I workout, specifically doing Squats, and Deadlifts. Also, I found that going to the bathroom for too long exacerbates it. The only...
It's the worst when taking it during class... I cannot concentrate and I also feel like a zombie...
Honestly, although you shouldn't change your life entirely, you may find it helpful to rid yourself of things that reminds you of him. Change your email address if you can, have his phone number...