I can say I'm feeling you right now. I'm in one of those no-motivation states and I know I'll be kicking myself later for that.
I think your main problem is that you don't believe there is something to work for in life. I was stuck in that mindset for a long time and I often thought of suicide as well although never extreme to the point that I would carry it out.
I'm in graduate school right now and pursuing my Master's in Electrical Engineering. I have everything going for me and all the love and support I need. Yet, I just can't find the motivation to pursue my studies. I know the importance of engineering, but no matter how hard I try I just can't sit down anymore and just apply myself to the material. I've done that all my life and now that I've awoken to the deeper aspects of life I feel like this is not meant for me.
So I think our problem is that we are doing something we don't enjoy doing everyday. That can have a drastic effect on our mental health especially on low-motivation days. Do you have any hobbies you enjoy doing? I think you can begin there to find something that will cheer you up. Motivation and ambition can come after that. But in our current state, I think we simply need something to cheer us up for a while and get our clarity back.
Hope you feel better man