How do you pick up the courage to change things?

Almost 3 now years ago I moved a couple hundred miles away to live with my significant other. Since then he has cost me several jobs and lied about being able to hold his half of bills, I've lost my car, my phone is broke and I'm too busy and broke working week to week to buy a new one, which is the reason why after almost 3 years here I haven't made a single real friend, and nobody in my family has talked to me for years. I feel lonely and I've lost all my independence.

At what point being unhappy in a situation is it time to move on somewhere else, even if the direct path to becoming happy is unclear? Is there a way to fight the financial struggle to get myself back onto my own two feet?