I had to rat on someone for the first time ever

Am I dumb for feeling bad about this?

I work for the government and I haven't even been there a year yet. There is an engineer there who was really nice and welcoming to me when I got there. He's from somewhere in the middle east so sometimes he has communication problems but its not that bad. Well after a while I started noticing that he doesn't really do the kind of work the other engineers do. He does stuff that basically an analyst or even a secretary would do. I mean I could do his job with a weeks worth of training. Just about anyone off the street could as well.

Now this guy gets paid about $85k a year. After a while I started noticing that he kept asking me to order cd's for the office. So I'd order them and then they'd be gone rather quickly and I'd have to order more, including cd jewel cases and even these special envelopes to send in the mail. I assumed he was doing some kind of software thing for work. I mean I was new so I had no idea. Turns out he's just burning cd's at work for himself. He literally sits there for about 4 hours of the day and makes mix tapes.

Then I noticed that he has no idea what he's doing with his work. People that are supposed to double check what he does are coming to me and asking me if I could just fix the typos and errors he has in his work. I told them no and I started to realize that the people that were there before me would just fix his errors and cover up for him. I told them I'm not going to be doing his work when he makes 3x more than I do.

Then he comes to me one day with a piece of paper with two lines on it that he wrote. It was an email he wanted to send to some company about buying a stereo. It seriously made almost no sense and he spent about 15 minutes writing it out. I was like dude do you not even know how to write english? He said he was just joking and it was an email he got from a friend. I was just thinking wow, how do you get a job as an engineer, making $85k a year and you don't even know how to write or do anything more than basic math?

Finally the straw that broke the camels back was when I saw that he doesn't hardly ever use his leave when he takes time off. In the last 2 months he has about 115 hours that are unaccounted for. Basically he goes on vacation for a week and only puts in for 8 hours of vacation. The rest is just money that he's basically stealing. He's stolen about $3k from the tax payers over the last couple months by not using his leave.

Now I'm not the kind of guy that goes and tells on people but this is just ridiculous. This guy has somehow had a free ride his entire life. He's basically stealing from the tax payers by just being employed by the state. Doesn't matter if he's not using his vacation time or not, he is getting paid a lot of money for mininum wage type work. I went and told my boss, without naming names, about the whole not using the leave thing. He wanted a name but I couldn't bring myself to do it because I can't stand rats in the workplace. I gave him enough info to where I think he'll figure it out. My girlfriend asked me if I felt a lot better now that I told him about it....to be honest, I feel really bad now and I'm not sure why.