I totally understand in some sense. I'm not working towards a doctoral but I know how it feels to be battling this and fighting to live a 'normal' life. First and foremost though, as theox mentioned, are you managing the bipolar? Because, in my experience, if you don't then that will always push through into your every day life anyway with unexpected consequences. I realized for me that it was really important that I didn't ignore or avoid my issues. Otherwise it would always creep in on my when I least expect it.
Ultimately, it's just plain hard and takes work. And I'm still working through it. It's not like you go to one therapy session and figure it all out. Or take one pill and it all becomes clear. I soooo wish it was that way. But I've learned the hard way that its not. However, I do believe, although I'm not there yet, that one day with hard work, my life will feel 'even'. I say even as though it's a sacred word. Because I truly believe that with being bipolar that my most valued emotion is to feel neither highly agitated (manic) or depressed, but to just feel even. To be in between. I want to feel balanced. And I think for those of us that live in the extremes that this is what we most want to achieve. Which is kind of funny because I'm sure those that are balanced wish the opposite. But regardless, I think we can all achieve balance somehow. And I think you'll get there too. But it takes hard work when you're depressed. And if I can figure it out then I'll be sure to let you know. And if you figure it out please be sure to let me know.
But in between please keep moving and going on as you are. And I'll do the same. And if you need a sounding board in all of this then please feel free to write me. But regardless this site id a great place to get support so keep posting here and venting with whatever you feel you need to! Good Luck in your journey!