Loneliness has a particular shape. It is not only being without people. It is the feeling that what is happening to you resembles nobody else. But most of what you want is not particular to you. You want to be safe, to be fed, to have someone hold you, to not be in pain, to feel you have a place with another person. You did not invent these wants. They came into life with you, and they came with everyone before you, and with many of the animals that share our characteristics too.
Try to look at them across time, and not only from where you are standing. Behind you is a long line of living things. Not one of them chose to exist, and even so they wanted many of the things you want now. Your fear is very old. The person feeling it today is new. The feeling itself is not.
This does not mean that what you carry is small or unimportant. A thing does not become less real because it is common. But it can become less strange. Being one of many does not mean you are nothing. It means you are not alone. You are not the first person to lose someone dear, or the first to know need and poverty, or the first to lose a job, or the first to fail an exam. More than that: you are not experiencing these feelings in some unique way, or for the first time.
There is something else you may notice. When you write what you are going through as something old and shared, the shape of other people changes too. The colleague, the neighbour, the person who was cold with you today, all of them are carrying bodies and minds they did not choose, and each one of them lives with his own fears and wants in his own way. They all resemble you, and they all pass through moments like these. You can pick some of the people you know who went through the same experience, and bring them into your writing.
A simple way to start: take the worry you are living with today, and write underneath it: I am not the first to feel this. Then write to prove that sentence. Write the names, the faces, the stories, and whoever you can imagine before you.