I used to keep track but have not lately. I'm in graduate school and working, super busy. Sometimes I think I just got used to it, but there are times when it is very strong euphoria, funny feelings on my skin especially face and lips. I moved states recently and have not found new doctors yet, but when I do I want to find someone in holistic natural medicine. I try to eat healthy and take my supplements which seems to help me have less of this feeling. When I exercise its better, so I need to do more of that.
My auras are visual and olfactory, but mostly visual. It starts as I notice a small blind spot in my vision, like when you have a camera flashed in your face but smaller, then it grows and looks like, I guess, light crystals that shimmer. This last one was just the spot and a little light flashing, it didn't grow over my whole visual flied this time. I was getting myself prepared for a migraine, when I just started feeling fuzzy and a little high: euphoric, and here I am, that feeling that freaked me out years ago. I hope it doesn't stay as long as it did then. The difference is now, it does not freak me out, so I don't have the other symptoms of panic and all the sensations related to that.
Do you suffer from migraine?
Depending on which country you are coming from, you may find food in the US good or bad. I find it worst (and I have lived in many countries). So eating healthy in the US is a challenge. It will take long time to get it straight and be prepared to spend money.
Grad student is not an easy job. My migraines started 3 years in Grad school that I was living on daily dose of Ibuprofen. My advisor (actually Boss) was one of the worst persons to work with, a bully and me being not assertive, was not fun. Now since last 2 years I took a break from my grad school due to parental obligation so I exactly know what you are talking here.
The aura you mentioned is exactly what I used to get. I never felt euphoric though, depressed on the other hand as I set myself a very high goal in the grad school and my boss was always playing a role in sabotaging for his personal benefit (and then blaming me for everything). You don't mention where you are at the moment (Good actually for the sake of your anonymity) but find a local neurologist and get a treatment ASAP. DO NOT LIVE ON OTC ABORTIVES, like I did.
If you are in northern part of the US, where it has already snowed and you are brown or dark skinned, consider Vit D supplement of 1000 IU/day, try a supplement of Mg (MgCl2 is what I take from Vitamin Shoppe, 200 - x -200mg) You exercise, which is very good, keep it up, esp cardio. Also, ask your neuro to refer you to a Ophthalmologist for a thorough examination. Most likely, everything is fine but just to be on safe side. And if you are close to any headache center, cut through the crap and go there or if you are close to Mayo Clinic, Jefferson Headache Center, Montfiore Headache center etc.
There is very easy fix for your problem, you just have to be patient. Start recording your diary again. Most likely, it will be asked if you visit any of these centers. And finally, if your Boss is the problem, be assertive. Life is more important than just a PhD. (If you have reached this far, you can certainly do more with your life, even without PhD.)