If your relationship is important enough to you to keep, I'd recommend making some adjustments that will give you what you need and hopefully some of what he needs. I also really need alone time--I can get irritable and snappy and downright ugly if I don't get any time to myself. My husband and mom know this and are really good about allowing me that. It's something I build into my days, and my support system understands that sometimes I'm going to say I just need to be left alone. It's ok to need that and it's ok to give that to yourself. Maybe your own room or some time set aside for you to be alone will help. Be careful that you're not isolating--that's a common thing for a lot of us and there's a fine line between needing alone time and choosing to isolate. One is healthy, the other is not.