Depression is due to negative thinking. If you want to NOT be depressed you need to be a positive person. You need to draw positive energy. My brother is a psychologist. He says one third get better, one third stay the same and one third get worse. There is nothing he can do to change that. But I think things like the law of attraction can make a difference.
Depression is two things: anger at the self, and feeling that your life is meaningless. Life does have meaning: it has the meaning that God assigns, it is the opposite of death, and the meaning of life is love and redemption. If you are angry at yourself, you believe that you do not deserve to be loved or redeemed, hence you believe that your life is meaningless.
I don't know. I wanted to go into another branch of engineering at first through the compSci program, but I failed in doing so. Now I don't know what I'd like to do, much less what education I'd like to pursue.
Why did you fail in going into the other branch of engineering? Would you want to go back into that engineering field if you could?
If I was perfectly healthy, I'd probably say MIT or Harvard, but now that I'm not, I would not be able to complete a degree at those universities.
I see that you wish to aim high for best results.
However, you never will be perfectly healthy, because you live in a fallen body. Perfectionism is crippling. Pursue ugly solutions and put the duct tape on your tubes.
Life is a series of patch jobs that you improve on, but if you expect perfection from your solutions right away you'll never do anything.
In addition, "I have no will to live so I can't do anything, and I can't do anything and thus I have no will to live" is circular reasoning which proves nothing and goes nowhere. You can do something, it just has to be small enough to get through your depression fog.
I don't know how to get holy by my own efforts...
You can't do that. Positional holiness (justification) is a free gift of God that is given at salvation.
Ephesians 2:4-9 said:
4 But God, who is rich in mercy, because of His great love with which He loved us, 5 even when we were dead in trespasses, made us alive together with Christ (by grace you have been saved), 6 and raised us up together, and made us sit together in the heavenly places in Christ Jesus, 7 that in the ages to come He might show the exceeding riches of His grace in His kindness toward us in Christ Jesus. 8 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, 9 not of works, lest anyone should boast.
As for behavioral holiness, that cannot be accomplished in this life, but we can improve toward that as part of the sanctification process.
Phillippians 2:11-13 said:
12 Therefore, my beloved, as you have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling; 13 for it is God who works in you both to will and to do for His good pleasure.
Expecting sinless perfection out of yourself is a quick recipe for depression indeed! Depression is anger against the self, and if you are angry at yourself for not being holy and perfect, that will definitely erode your will to live and put distance between you and God. The bottom line is that you are as holy as God wants you to be, and your goal should not be sinless perfection, but to improve in holiness.
If this is indeed the case, you will need to pursue the ugly and unacceptable solutions and fight your feelings and body in order to move forward. There are no perfect answers, only ugly solutions that become less ugly with time.