I too experience dizziness (and blurry vision) on Entocort. It really sucks, doesn't it. One possible reason is that Entocort could be making you hypoglycemic. When I started Entocort I was on a liquid diet. I was drinking six Ensures a day. The Ensures are so loaded with sugar I was stumbling around, afraid to drive, slurring my words and so, so, so dizzy - It was like I was drunk! Try to see if the dizziness is worst after a meal (or gets better when you eat) I know that I can control it (a little) if I eat regularly and stay well away from sugary stuff.
As for the mood swings... I get them too. My roommate calls it my Roid Rage... Which always makes me laugh.