My advice would be: let your mind run wild and adopt an attitude of "oh well, big whoop.... it will calm when it's ready to calm down".
Since 1992 I would have intense bouts of depression. Saw more counselors, psychologists, and p-docs than......... uhhh.... a squirrel buries nuts?? I got nothing.
Anyway.
I stopped looking at it like something that needs to be fixed by me. Sure, it feels terrible. It saps/bleeds meaning and sense and enjoyment and peace (and all of the good shit) out of your life. But, the idea of letting it be and getting back on with your life changed things for me.
And that's where character comes from: doing things because they're right to do regardless if there's an emotional upswell supporting those decisions. But even more so, because, your 'feelings' about it are not so much as 'not there', but, they're rapidly pulling you in the opposite direction.
I don't have some steely resolve now.... but, I do have a more fundamental sense of peace in my life. A sense of peace that isn't contingent on my feelings needing to moor me to whatever decision I decide to make. And, similarly, though while it's great when that positive emotional upswell is there, I no longer am as much a marionette doll to those emotions.
I second this general philosophy.
I've been dealing with bouts of depression since my teens, although to be fair, I've never got to the point of suicidal thoughts. I've been to the point of not caring if I live or die ("I could quite happily just disintegrate, right now" type of thing), but never to the point of taking any action, so it may be a little different to what TS is going through. If you're having actual suicidal thoughts, you need to get professional help, IMO.
My worst patch was when I truly, absolutely came to terms with the size of the universe and my very temporary, completely insignificant place within that universe. I'd always "known" that, but once you truly, really accept it, it can fuck you up. I'm an artist and my art has always been my salvation. No matter how bad things got, I always had that to fall back on. But suddenly I realised that even if I was the greatest artist to ever live... It doesn't matter. At all. This entire planet could disappear and the universe wouldn't even blink.
Nothing matters.
That fucked me up for a good while. Several weeks and months of despair. Days of just lying on the floor, staring at the ceiling. Then, all of a sudden, I realised that if nothing matters, the fact that nothing matters... Doesn't matter. Nothing had really changed, merely my perspective. Nothing had been stolen from me, because I had nothing to begin with. After coming to that realisation, I felt a lot better. I no longer create art with any kind of hope of success, more just as a selfish, hedonistic experience which I enjoy. And generally, I live my life in a similar fashion.
But that's what I call "intellectual depression", where you philosophise yourself in to a depressed state. So, while that isn't so much of a problem anymore, I do still deal with periods of "physical depression".
My breakthrough with my physical depression happened after going through what was essentially a panic attack, which used to happen frequently. There'd be something, anything really, that would set it off. Something would annoy me during the day, or I would just feel illogically irritable. A tightness would form in my chest and it would slowly build, until, inevitably, I'd explode in a fit of crying and hitting myself and/or walls etc.
I'd always end up swirling around in a cycle in my head, wondering why all this was happening. Trying to find the root of it all. Because, my life is objectively really good. I have a home, a safe neighbourhood, a job I love, a woman who loves me etc etc etc... And yet, I was still dealing with this depression bullshit. Why? Well, I could never find a good reason, which would just frustrate me further, which would increase my desire to work it out... And so on. Just a snowballing problem.
Then, one day, I was staring in the mirror, tears streaming down my face after a particularly bad attack, and I vividly remember looking in to my eyes and just accepting that this is who I am. Sometimes this happens and I freak out, or I feel like a piece of shit... For no real reason. It's sucks, but it's ok.
And ever since then, while I still have days where I wake up feeling awful, I just recognise it for what it is; a bad feeling that will eventually pass.
With physical depression, it also helps to recognise what your body needs to operate; sleep, food, water, sunlight, exercise. Those are mandatory. For everyone. You skip out on one of those things and you're going to suffer for it. It's become something I'm very aware of. If I'm going through a bad patch, I can generally look back over the past few days and there'll be something out of whack; not sleeping, not eating right, not getting enough sun etc.
Yeah since I was an adolescent. I envy people that were able to push it aside enough to establish a life, as the busier you are the harder it is to focus on how you feel all the time. I hit a high point about 4-5 years back where I thought everything was going to be fine, then my life basically just disintegrated.
Anyways now I just focus on my education, I tell myself to worry about getting my degree and becoming financially stable and everything will fall into place from there.
Tbh it's completely unsatisfying though. I have no passion or interest in what I'm trying to do, so I'm trying to forcefully cram this information in my brain that I don't give much of a fuck about. And then I have no friends and have been single since my marriage blew up, so on a day to day level there's just nothing to look forward to. It's some groundhog day shit.
So wish I could offer some inspirational hallmark card stuff about how it all gets better, but in my experience it really doesn't. I'm half focusing on the future and half just waiting to die.
My two cents... Don't bother pursuing something you're not passionate about and interested in.
Life's WAY too short to fuck around with any of that nonsense. Do what you love. If you love it and work hard at it you can make a career out of it. Guaranteed. You'll also meet a lot of similar people who will be in to the same things as you, for the same reasons.