can it cause depression when someone realizes that they are going to spend they e life alone?
No… It can cause depression when someone THINKS they are going to spend their life alone. But consider this a chance to get to know yourself. When you learn to like yourself as you are, and begin to show confidence in that, you might be surprised how quickly that draws people to you. Don’t try to fake it, either. People can tell, somehow. Write. Write poems, songs, stories, journal entries, whatever. Just write what you’re feeling. Give yourself a chance to learn what you are like by this. If something is REALLY bad and you cry when you write it, file it away somewhere, so you can look at it later, when you’re stronger, and realize just how far you have come. Learn to like yourself. That’s the key.