Severe abdominal pain after all you can eat beef ribs, should I go to the e.R.?

Yes. Yes. . You've said "severe". So go. And don't wait for a web site to tell you to use common sense. Please.
Need more info. I need more info to make that determination but if in doubt it would not be a bad option. Generally speaking it sounds compatible with gallstones which will likely require ultrasound or other studies to confirm. For the most part, this can be dealt with electively but if you have severe pain associated with fever/chills/nightsweats, etc, an er visit may be appropriate to treat impending rupture.