How can I carefully tell my Boss to stop being a @#$%^?

There is a wee bit more to the story. You know that, and you didn't offer the other side of the coin. No prob.
If there is dissention between your immediate supervisor and yourself, then YOU have a problem employment-wise, and he does not. HIS job is secure for whatever reasons.
Regardless the inside and regional stuff between you and he/she, my recommendation would be to consider spending some time when you are able, to find another occupation, or just a job, either temp or whatever.
Most people placed into supervisory positions over workers that they once were, tend to deem themselves "more important" and suffer dillusions of grandeure, especially when "Uncle Fred" owns the company.
This may not be the case, but if you have crossed the boundaries of concern for your worthiness and/or usefulness, you would be well-advised to seek employment elsewhere, because this stuff doesn't blow over EVER!
In the event that you submit your resume either verbal or written, (depending upon the requisites) do procure copies of past employment and letters of accomplishments. It is illegal for a former employer to state your forfeiture of employment as being either personal, or lack of abilities, and if you are unable to find gainful employment due strictly to a "bad reference" from the past employer, you have grounds to sue for defamation of character and liable.
That job sucked anyway obviously, so take some time to look around, get some interviews. Your current employer "CANNOT" fire you for seeking gainful employment, lest they stand to be liable for hindering your rights to work elsewhere, and you stand to file for unemployment benefits anybutt, well-deserved if you've been there more than 3 to 6 months. Turn in your one or two-week notice as is stated in your contract of employment, and get the freek outta there.
We've all been there, and it is hard to know that you may have to go a week or even a day without incoming bucks, but keep your head up. It will pass. In a year you'll be laughing about it. Pissed off at the jerk still, but he's the one who lost an excellent worker.
Inform the "BIG-BOSS" that you are experiencing some either personal or other difficulties with your job, and you would appreciate a letter of recommendation, which is their obligation by law, and thank yous for the opportunity to work for their great company. Cordial is smart. Big bosses look at that stuff. Supervisors get their butts chewed for the loss of those who appear to be intelligent, gracious, and educated. Show the bum, and move on. You'll think about him every Christmas. I like to send a card every year. Strange how I never get one back. Heh.
Best of blessings for you, and yours'.
On the other hand, if you like your job and you wish to stay there, request an immediate meeting with your "BIG boss. It is his obligation by law to comply. The evening before, take the night, and start writing and practicing your speech. Clear the air early by being nice, and cool. Then express your concerns. I can guarantee that you'll know within the first minute or two whether or not you're wasting your time, because he'll either cross his arms at you, or he'll request you to stay. It will only go one or the other. Thank the jerk for his time and start looking. Don't be right. Be smart. Tough world it is.

Nad