I can totally relate, Dogmama! I retired last August (2011) a week before we moved down to Belize. Since then I've been blogging, and we have been traveling whenever finances allow, but I have been bored a lot of the time. Not used to that! I recently volunteered to be the webmaster for the local humane society, but the amount of time it requires is minimal (5-6 hours a week or so). I am not "officially" allowed to work or volunteer here since we are not permanent residents, and the government does not want anyone on a tourist visa to take away work that a local might be able to perform, even on a volunteer basis, which is so strange to me. But no one thinks they'll notice or care about a behind-the-scenes webmaster role, so I was willing to take that on.
It's definitely a very odd-feeling transition to suddenly not be working after working my entire adult life. I was used to being "needed", being a part of a team, drawing a good paycheck, having insurance through my job, and all those little perks that come with it. I was also very, very tired of the politics and even of the work, which, by the end, was just changing so fast and becoming less and less engaging for me than it had been in the earlier years. I was a software engineer in the telecom industry, and it's really a job that is geared more towards the 20- and 30-somethings who are willing to put in the killer hours and are up on all the latest technology. In my last five years or so on the job, I felt old and out-paced by the younger folks being hired. I was ready to leave and overall don't miss it, just certain aspects of it. If I were offered my old job back, I wouldn't take it.
I read a lot of articles online and found that it's incredibly normal to feel a real loss of "self" when you retire from a career you've done for years or decades. It's not just us. It takes time, too, to find that next identity. I am still working on that part. But I do know that even though I miss the structure of work and many of my co-workers, I don't miss having to go to work every day, having to get up with an alarm clock, the politics, or being told what to do all the time. I can't imagine ever going back to that.
I hope you find your way, whatever it turns out to be. From what you've told us, I think working with dogs would be a fabulous niche for you. Once we are no longer traveling much, I would like to volunteer to work with a Boston Terrier rescue group myself. There are so many opportunities to make a difference that do not involve drawing a salary! I don't think I'd ever go back to school or start another paying career unless I needed to financially. I feel very fortunate that I don't "need" to work for money as I was able to earn a good salary and sock a lot of it away over the years, and DH and I have lived below our means for our entire marriage (27 years so far).
Best of luck as you figure this all out!