Eating out is never easy, but does get better with time as you get more familiar with the carb counts of various foods. In time you will even get into the habit of ordering similar things when you go to a certain restaurant and knowing how to bolus for it. For now, you need to be sure you have an accurate I:C ratio which may differ for each meal. (Mine are 1:7, 1:9 and 1:18 for the three meals). To do this you can start with 1:15 and then test and see how you do and recalculate it up or down accordingly. For me, as a type 1 there isn't a lot of variation in my dose as 5 units is the most I ever bolus, but I know type 2's usually have larger doses. My suggestion is to under-bolus rather than over bolus if you are uncertain when you are out, to prevent going low. I also often wait until the food comes so I can look at it rather than bolus 15 minutes I do at home (also because you never know with restaurant service when the food will actually arrive). I have some pages I copied out of a book that wouldn't be too hard to take with you and for you smart phone users you could look it up online (calorieking.com). Again, with time, it will get easier as you will instinctively know how many carbs are in familiar meals.
It is very hard being a diabetic. One of the facts of life is that you cannot (or should not)life a "normal existence" in terms of diet.
Modern business often requires dining, as "part of the job", but it is not a good idea to ignore the requirements of the disease. It takes will power.
You can standardize the values of a quarter pound hamburger with onion (or a slice of cheese) and a small salad, for example.
As Zoelula stated, you need to get familiar with car values of different foods and get in the habit of ordering similar things. Zoelula's suggestion on I:C ratios are on the money.
It is important not to be alone or start driving somewhere if there is any chance you have used a larger bolus than appropriate.