I smoked weed and got depressed over my ex. Is that normal?

I am currently in the process of recovery from my ex of 2 years (we broke up a couple months ago) in a very hurtful breakup for me . I've been emotionally unstable for the past couple months and ive been avoiding things that remind me of her diligently. Now, last night I smoked a lot of weed with friends and a song came on that reminded me of her. I immediately got really depressed and I felt like I did right after the breakup. Was this just because I was high or is this really how I feel.