Hey Mek, my experience with meds for bi-polar, which was misdiagnosed: I felt that "even" feeling, it felt sort of like a void. Nothing spectacular, nothing horrible. Everything just - so-so, all the time. At first it was a relief, because having "episodes" of frustration and panic is exhausting and this prevented them. Eventually I got bored of being "the same" all the time and determined that life isn't supposed to feel this way, so I got off it and learned to manage my emotional experiences, and get a more exact diagnosis. (Functional ADD, no hyperactivity). I don't take meds for it anymore but I do take Ambien to sleep, because my brain lacks that ability to set aside thoughts to some other part of my mind so I can stop "actively" thinking and fall asleep.
I still have frustrating moments, they seem to be increasing in frequency now that I'm officially "old" (menopause complete). I'm better at handling them now though, most of the time I can just physically remove myself from the source of frustration and get a grip on my frustrations, then go right back and deal with the situation without falling apart. When I can't physically remove myself I can practice a few relaxation techniques. Like if I'm driving in bad traffic and have to pee and there's an accident up ahead and some moron is beeping his horn behind me - I can calm myself down enough to not be reactive.
In short - being in a "zen" moment 24/7 sounds great to most people who aren't forced to be in that moment 24/7. But it's normal to have moments of jubilation, joy, pride, happiness, and normal to be horribly hurt or sad, and it's also normal to occasionally feel shame, regret, sorrow, and a sense of futility. Never being able to feel these things due to meds makes a person feel less human. What you need is something that will allow you the full spectrum of human emotion, but will block off the "reaction" signals that make you carry those emotions to extremes. Behavioral management and cognitive therapy can help but they won't solve the problem. Meds are also a tool - not a cure. You have to find the right type and dosage. Work with your doctor (or get a new one). Also - during moments when you would normally be especially upset about something - and the meds make you not especially upset - try and embrace that "it's a really bad thing that's happening but I'm able to handle it" feeling.