That's not characteristic of BuSpar at all, so it's unlikely that's the cause. You didn't say how long you've been on the BuSpar, but it generally takes about six weeks for it to be really effective (for me, it's a miracle drug - even my co-workers have commented on how much calmer I am on it).
We are all unique little chemical mixing vessels. Everyone brings their own individual body chemistry into play, along with everything else you're exposed to, ingest, etc. No one can predict how someone else will react on any particular drug regimen. I will say, though, that I've heard many more people on Prozac especially who have the same complaints as you mention in your question. Try different antidepressants. Serzone worked for me for a long time, and it doesn't have the anxiety-inducing quasi-manic effects, nor is it quite as sedating as, say, Paxil can be.
Some people can't take SSRIs but have good luck on the older tricyclics. One of my sisters has been on a tricyclic med for over 20 years. If she goes off it, her symptoms return.
I'm not on any ADs now myself (just the BuSpar for anxiety), but I had a nearly 30-year history with them. I had my best success with Serzone and then, when it quit working, Wellbutrin. Wellbutrin is contraindicated for anyone who experiences manic episodes, though (I don't - I only go down, never up).
Time to talk to your doc about trying something other than Prozac, would be my advice.