I took something that made me feel like I was just in an other world. I would just start staring off into space and it made me tired and I was totally not alert, plus I felt aggravated to the extreme when anything annoyed me. I couldn't live like that with three kids, so I had to stop taking it. It's better to be just spaced out than not take it and be flying off the handle.
Like Marvel said, if you give it a little more time, it might get better. If it doesn't, your not the only one who has to try to find a different medication to suit you. Sometimes you just have to patient to find out which one is best. Make sure you talk to your doctor about all the effects you have, plus you might want to not do anything dangerous, like driving, if you are spacing out too much to concentrate.