I'll admit that I've never joined a writing group - the idea of them kind of scares me!
As a way of getting the idea down on paper, I really recommend it! I've done it for a few years now and for a while it was probably the only writing I did each year. I wrote so many stories that would've never otherwise seen the light of day (although you could argue that was for good reason

) and it's actually a lot of fun too. Particularly if you reward yourself with something at the end.
It's funny, when the only pressure is to write quantity, not quality, it gets a LOT easier to do it. Quality can come with editing, but you can't edit what's not there.