How to DEFEAT depression - a work in progress

I am calling this a work in progress because I am currently in a seriously fragile mental state - most certainly the most fragile state I've had to deal with in my life thus far.
I am 22, I am reasonably healthy, I am studying and I have an income. I have the most supportive family in the world and for this reason I can't understand why my mind is slipping to such dark places. I don't want to die - in fact, the thought of death itself is almost the entire basis of my current situation.
I'll tell you how I am feeling - I am feeling hopeless. I am feeling like life is so ridiculously short and we, as living humans, have no way of knowing that anything will happen after death. The thought of a world without my loved ones in it makes me incredibly anxious. The realization that I will not live forever is overwhelming.
I think a big reason this is causing me such mental harm is because death is the the ultimate truth. It is on the absolute top tier of things I have no control over.
This state of mind has been going on for probably about a week or so now. Maybe a little more. I've spiraled down a little but I am getting BETTER.
Here's the good news; what this dark period has taught me:

• there must be a higher being. life is too beautiful for this to all be science
• fame and money is not everything - I would feel this dark feeling regardless of my wealth or success
• my soul is growing - I am understanding more about the world and about the beautiful spirits around me
• fear of death is normal - no one can tell us what happens after.
• stop worrying about things you have no control over - live your life to the fullest and greet death as an old friend
• turn these feelings into ART. I have books to write, dammit!
• writing is my ultimate therapy
• stay POSITIVE. YOU WILL GET OUT OF THIS DARK PLACE. THIS TOO SHALL PASS!

I've seen a therapist in the past but I don't think I felt near as bad as I feel right now. I feel like she didn't help me anyway. I had to get myself out of the hole, and I did. Granted, I took a lot of MDMA but the point is I know this feeling is temporary and I alone hold the necessary tools to fix my problems.
I'm already a lot calmer after writing this blog entry. This has been the clearest demonstration that writing is the best therapy for me. It's important to know that different things work for different people. For you, seeing a psychiatrist might be your best option. I'll always suggest people try that first, but psychiatrists aren't miracle workers - you need to put in a lot of the effort yourself. You alone hold the keys to your happiness.
I'm not going to get better overnight. I've got a lot to work on. I think changing my diet and exercise habits will be a huge help. I had dental surgery three days ago so I won't be exercising for at least another few days. I know that seems like an excuse and it probably is but I'm happy if I am drinking more water, which I am.
This probably seems like a long, rambling mess, which it is. I am a writer and I haven't written in so long. My future posts on the topic will continue to become easier to read and understand.

Welcome to my blog, we're just getting started.