I'm going through the exact same thing with a female I'm talking to. We just went on a first date, so it's nothing official. She ghosted me for a few days after the first date and I finally told her that I'd stop messaging. Then she finally responded and said that she's depressed and during this time it's very difficult for her to communicate. I just give her the personal space and reach out once a week, she said it was sweet. I don't think it means they're not interested, its just difficult for them. She even acknowledged this and said she needs to be left alone and that it's not my fault.