In my experience, certain strains are better for anxiety and panic attacks than others. I find that strains which are higher in THC can cause anxiety in some people, but I personally have only had this happen once or twice a long time ago, and I always wound up having reasons to suspect that I may have been laced. However, I digress...
I would look for something that is higher in CBD, and mid to lower in THC (anything from around 15 - 19% shouldn't be overdoing it, in my opinion). I personally find that many Hybrids are just as effective as Indicas, providing of course that I pick and choose my strains. I find that the Sativas tend to be more of a heady, mental high than a physical, body centric one. As such, it is the Sativas that I would avoid: they seem to be great for putting me into a relaxing state wherein I am less stressed out, and panic is less likely, but reveal themselves as altogether useless when my heart is pounding, my palms are sweating, and my pulse feels like it is going to propel itself outwards through my temples. In other words, I would use Sativas (or the more Sativa-dominant Hybrids) for relaxation, and putting myself in a peaceful frame of mind, but would go to a heavy Indica if I was in the middle of a panic attack and needed sedating. In summation, I don't worry as much about Sativa versus Hybrid versus Indica, but more about CDB versus THC. I also find it worth noting that many of the strains at my provider are listed as being useful for stress, while others are listed as being good for anxiety. It seemed a little silly to me at first, as I thought for a moment that they were largely the same thing, and they are, but it comes back to what I stated above: it would seem, for me at least, that the strains that are indicated for stress are good preventives, but very poor sedatives; I stick to those listed for anxiety if I seek something to calm me down whilst experiencing anxiety and panic.
As far as a level of being medicated, this is very subjective, as you yourself so eloquently put it. I personally find that ~0.30 grams in any of the vapourizers I own to be perfect to get me where I need to be. This may be very different for each and every individual, so my advice to you would be to start small, and experiment, since you can always increase your level of medication, but you cannot reduce it if you've overdone it. Perhaps 0.10 gram increments would be advisable.
I would love to suggest specific strains for you, but since my provider no longer uses slang, or street names for their product, it makes comparing their strains to those of other providers nigh on impossible. There is one strain which I have found to be good for anxiety, that they refer to as Red #4. I am fairly certain that they were initially calling it "White Shark".