You ask me, who would want to be with you. Exactly what do you think is wrong with you?
Your parents are ill (this is a very taxing experience). You broke up with your girlfriend, clearly because the relationship wasn't meeting your needs (a very brave act). And, you had the nerve to change jobs (yet another brave act). So, basically, I see a strong woman who is dealing with an enormous amount of life stress.
So what exactly is the problem? You are engaging in self-attack. You are berating yourself with self-denegrating thoughts (who would want me?) about being all screwed.
I must tell you that the only thing that is screwed up is the way you are putting yourself down. How come I only hear about your self-critical feelings? Where are all the rest of your feelings? Your dad and mom are sick, you lost your girl and your job. Where is your sense of grief, loss?
And while were on the subject of feelings, what happened to your feelings of anger. When a person engages in self-attack, she or he is usually angry and doesn't know it. And, what happens next is that the unrecognized anger gets misdirected, in the form of self-attack.
Your next move is to figure out who you are angry with. In your case, it sounds like you could very well feel mad at the entire universe: at your parents for being such burdens; your ex. for having disappointed you in love; at your job for not having met your expectations.
Remember that angry feelings aren't wrong. They are irrational and they come at go at their own will. Either you will own them or they will own you. At this point, they are owning you.
So, here's your 'funk therapy.' Discover who you are angry with. Own and accept the feelings. This will help you stop self-attacking, and when you stop sitting on yourself, you will find that the funk will start to lift.
Keep me posted on how you do.