I've just pegged what this feeling is. . . 

I'm a college student at a private university.  I've maintained a 3.9 GPA, I just signed the lease for a house, I'm the daughter that my parents don't worry about. 

I've felt a heaviness inside of me for at least two years now.  Every once and a while I talk to my parents about it and I'm like, "could this be depression?"  The thing is, though, I always tell myself to suck it up and keep going.  Even if I don't want to do something, I recognize that I have responsibilities.  So if I am depressed, I'm functional. . .  meaning it's never actually been dealt with. 

But today, I was able to recognize what this "heaviness" means.  My brain just went, "OK, I'm done now.  I'm ready to die."  And as soon as I recognized this, it actually felt like it lightened. 

I'm just so tired of being strong.  I've had to be strong since I was a toddler.  I was sick for the first half of my life and the doctors actually didn't think I'd reach adulthood.  I feel like I've been toughing out my entire life and suddenly I'm just going "no, really, I'm done." 

Hi Leigh,
the heaviness you speak of is all to prevalent in my life, except I just call it the dark place.  Admittedly my situation is vastly different to yours.  Im a 50 year old separated male.  I have battled the dark place for a long long time.  For the first 30 plus years, I didnt like to admit there was an issue there.  Except of course I would get these... moments of absolute anger.  And as I got older the anger just got longer and longer.  Eventually I had a situation which led to me being diagnosed with depression, and 10 or so year down the track, even with medication, I still fight to stay away from the dark place. 
It doesnt matter what our background is, the darkness is there for some of us. 
I hope this helps. 
Happy to share experience with you if you want. 

Leigh, when depression gets to the point of suicidal thoughts like you're having, and then you feel "lightened," it's because you come to the "realization" that "i have that option to die."  You'll start thinking of it as a last resort, something that's always available to you and in a way, it's a "positive" (it's not, it's just how our brain thinks).  You should seriously look into meds.  You're clearly a very smart person and you've got those chemicals in your brain that have you thinking the way you are, meds would seriously help.  I hope you'll look into it. 

Yes, I feel like this sometimes because it seems easier to have a way out, but we need to keep fighting through that feeling.  If we cross that point, we can't go back and change what is bothering us...so I hope that you will reach out and get help so that you can start to feel better. 

Thank you, everyone, for understanding.  At this point, everything I have been feeling has been heightened by the confusion involved in trying to process it.  I truly appreciate that the three of you have been able to make sense of what I am explaining. 

I will talk to my parents about it again. 

My prayers go out to each of you: that you will be blessed in a way that can only be recognized as God's hand touching your lives.