I suspect that work has nothing to do with this, more likely the negativity and the real reason why you're so obsessed with work. I think work is your crutch, not your problem.
* And now it's 2:31am on a Sunday evening and my girlfriend is in bed wondering why I won't come give her a cuddle, but I can't.
Most people are asleep then, that, by no stretch of the imagination is "evening".
You need to stop whining and get a job. Learn how to be a person, relate to your girlfriend, balance your interests, sort your shit out. Whining to the hn crowd is not the way to sort your life out, you need to stop looking to others to sort things out for you.
No business person with any chops is going to read this and want to go into business with you. You can't sleep, you can't keep your end up in a relationship with your girlfriend, you've been working five years and have only $5k to show for it, you've admitted to failing at everything!