Alexander, you said it yourself in your post: you have no income. No apartment is going to approve you with no proof that you can pay them. Can you blame them? Are you here in the US on your own for studies, or with a program? Is there someone here in the US who can sign a legal guarantee for a lease, that they will pay if you cannot? I’m sorry that it’s been difficult to find a place to live, but you’ve got to understand the landlords’ side of things.
