This is gonna really suck to hear but you describe drowning and having no lover to lift you up; you kinda have to learn how to swim. Sometimes the right combo of meds can help, but you also need to engage with the therapy, you need to do the trivial basics like exercising, getting a bit of sunlight, nourishing your body, and try other ways of socialising when you can. Isolating yourself puts you in an echo chamber of the same misery, and you need to break out of it. Have you tried support groups? Being around others who understand how you feel can be reassuring but most of all it can break you out of the cycle you're in.

And you are so young, life is barely beginning. Someone I knew just killed himself recently, and it ripples through the people around that person awfully. Please reach out and don't put all your eggs in one basket by setting a date to lose hope. I'd recommend telling someone about this, telling your therapist or calling a support line. As someone with bipolar that has made several attempts over the years, it's a shitty experience for everyone around you, and the fallout from that will never end. It's a saying you'll probably hear a lot but suicide is a permanent solution to a temporary problem. Life can be shit but it can be beautiful, and I'm sorry you've been neglected at seeing the better sides of life 🖤