I second what Ralphie said. Since you've already worked in some law firms, you have some idea what the job involves and if you were never sure about it in the first place I'd say that's a pretty good sign it's not the best job for you. From where you are now, it would be another four years until you qualify, assuming you got your FE-1's first time and an apprenticeship, and that's getting harder every year. Unless you're in the bigger firms, you get barely above minimum wage for those years and in many firms all the most boring work. Lots of people go into it becuase they drifted in, their parents wanted them to or for the money or some kind of status. That's not enough to make you happy in it when, as Ralphie said, clients get mental on you! You'll see from posts in the mortgages thread about solicitors fees the kind of regard we're held in by a lot of people, so don't do it for any notion of status...Clients often don't understand what we're doing or why and in my experience tend to assume we're being nit-pickers, lazy, incompetent and overcharging them.
I work in a small place where I am out every day at 5:30 so you can have decent hours, but most people I know work longer. A lot of the work is routine, especially at the bottom rungs and it's very detail oriented. A lot of people (myself included) skipped over that part of the job description, but it's hard to concentrate on it every day if you're not naturally a nit-picker!! Also, I don't find there's any creativity in the job. Maybe some people do but I don't see how. If you need a bit of that, you may get bored.
The money is about €40k in Dublin when you qualify, less down the country and more in bigger firms. It's good until you realize most of us have massive debts from trying to live in Dublin and have a life for about four years on terrible money. Most people have their fees and some hangovers from their Australia year to pay off too.
Buzybee's advice is good. You have to put in the time thinking about what you're good at and like doing and start from there. Use the What Colour is your Parachute book maybe, but you really have to put the effort into it. Don't get bogged down in picking one job title too soon. There are lots of ways into most careers, you may not need to do a Masters in anything so keep your options open. I think you should know what work you want to do before studying for another year and paying a lot of money for a masters. Maybe try a short evening course in psychology, while temping or something, since that appeals to you, to test the idea. Or go talk to one and find out what it's really like. A solicitor I once worked for would've loved to be a child psychologist instead....
I sympathize with not knowing what you want to do, I'm totally indecisive and still working on it. It is unsettling, but you'd be amazed how many people are in the same boat, whatever age they are. Good luck!