I don't really understand this and it's really frustrating. 

Just turned 20 and on prozac (have been for years) if that helps anything. When I take care of myself less my depression is mellow enough. Sucks, stops me from doing anything and I lay in bed mostly but yknow. I'm able to manage slightly. 

But whenever I form healthy habits the violent need to commit suicide comes up eventually. Like exercising daily, eating healthier, and socializing more. I've been doing so well this week and then since a fear hours ago suddenly felt the need to commit and its so hard to distract myself from it. I'm lucky that this time I don't have any means to kill myself right now unlike last time but its still hard to deal with. 

Why does this happen? It feels like I'm being punished for doing what I'm supposed to and like I'm just supposed to die. Like I can't escape it no matter what. How do I manage and control this? 

Any help or advice is really appreciated.