Does anyone here have a problem holding on to their job?

I’ve changed three jobs in fourteen months. One was awful from the start, but two others were pretty decent at first. I feel like I don’t belong anywhere. My team skills are nonexistent, I do my best to fit in with my colleagues, but it never works. At first, everyone is polite, but sooner or later I always begin to feel I’m an outsider in their conversations. I keep to myself, I’m not a sociable person, but people judge me as too private and unfriendly. I try to focus on the work instead, and at first the prospect of earning money and learning something new excites me. I obsess about new tasks and challenges until I burn out. Then it comes to the point when there’s nothing more to learn, I feel bored, and from that moment on, I literally make myself do the bare minimun while feeling guilty and unsatisfied. I hate the routine when I do things mechanically! The guilt and exhaustion build up, and I quit. Every time I tell myself next time I’ll stick around, that it wasn’t my kind of job… It’s very stressful, and I begin to feel ashamed of myself.

I would like to blame my ADHD for it all, but it’s not a big enough excuse. I feel useless and drained.