Detached from reality

I don't normally run to a forum for things like this but I won't be able to speak with a doctor about it for awhile and it's really bothering me not having any idea what's wrong...

A little history: About 5 years ago I went through a terrible, terrible breakup and I fell into a pretty bad depression for a few months. Among the many things I was going through I developed a weird sensation of being really disconnected from reality. Like I knew where I was but it wasn't real, I'd hear a favorite song and KNEW it was a favorite song but couldn't seem to pinpoint WHAT song it was or any of the lyrics, etc. The mother of my best friend told me that my symptoms sounded like a kind of Dissociative disorder but I never went to the doctor for an actual diagnosis. It passed once I started getting over the painful breakup so I didn't really think too much of it at the time.

Since then the same "detached" feeling has come and gone on occasion but never to the extent of that first time and only usually for short periods of time when I'm really stressed. My current concern is that it's back now and with seemingly no real trigger. It came on very mildly a couple weeks ago and was on-and-off for the first week. Now for the past few days it's been progressively getting worse. I've had a pretty rough year or so but what I'm going through lately is nothing out of the ordinary of my usual stress level so I'm at a loss as to why it's happening now or what it even IS.

My current symptoms:

Feeling slightly detached from reality/foggy brain
Forgetting simple things/details I don't normally forget
Trouble concentrating
Occasional feelings of anxiety/that sinking feeling in my stomach
On and off feelings of sadness/loneliness

A friend of mine has ADHD and is prescribed Adderall for it and when my symptoms first started showing up a few weeks ago she gave me one pill at work so that I could do my job properly and it did seem to help for awhile but after if wore off my symptoms were back. I don't know what's wrong with me but it's starting to affect my work and social life. If anyone has any clues as to what is going on in my head, I would REALLY appreciate any hints. Thank you!!!!