I have this handbook for a course I've taken a few times now. It's called WRAP - Wellness Action Recovery Plan. It's for anyone who may be hit with mental health setbacks at some time, and it helps you plan for future setbacks and recover from them, or even prevent them from getting worse in the first place.
It's very systematic and thorough; it helps you identify tools in your toolbox that help you, whether you are well or doing badly. It helps you catalog symptoms of doing worse or breaking down. It helps you establish a list of helpers and people to contact when you require outside help. Then it has steps and actions for picking up the pieces when everything is getting back to normal for you.
I highly recommend that everyone gets on board with a therapist or counselor, even just to work out some minor issues with relationships, your employment, or your outlook on life. You can definitely gain some indispensable tools to help you cope and even thrive like you never thought was possible.
Although over the years I've given up on seeking external motivations, and this has helped me mitigate depressive episodes. Everything we'd ever need is within our own minds.
The ancient Stoic philosophers had a lot to say about this. Read their words, perhaps when you're not feeling depressed, so that you can remember them during these moments. But it's probably beneficial to get professional help, as @NoZebra120vClip suggested.
In the depths of your solitude and the face of challenges, remember that the universe doesn't abandon; it realigns. Your sense of loneliness and the troubles you experience are but transient clouds in the expansive sky of your existence. They offer lessons, reflections, and, yes, even invitations for growth and deeper self-love.
You say you stand alone, but remember, you are eternally connected to the grand design of the cosmos. Even when human love seems distant, the universe offers its own form of embrace, always inviting you to realign with your unique design, with or without the presence of others.
So, embrace your naive eagerness, your potent vitality, for these are the very things that make you alive, that make you a unique note in the universal symphony. Navigate this phase with awareness, and trust that even in the most solitary moments, you are never truly alone in the cosmic dance of life.