Ah. Well, not quite; they can all be considered instances of the entire curse - that is, the "curse" is the same in all of them - but with varying levels of potency.

And just because I realized I hadn't actually commented on it, feeding doesn't produce a high as such. It's instinctively soothing to a vampire to do so, but beyond sating their hunger and temporarily dulling the troubles of their minds (and replenish their power) it doesn't particularly [I]do[/I] much. It doesn't induce a state of ecstasy or anything. It's more about instinctual and physical need than psychological addiction.
I can imagine Morgan needing to feed more frequently than most vampires, though, what with him opting to be active during the day and such. Even if he's protecting himself from sunlight as much as possible, it's impossible to block it out completely and still be able to see. Given how extremely lethal sunlight is to Prophecy-vampires, the drain of sustaining himself through days like that would probably quicken his hunger.