If you were working with a customer shirtmaker, that may be your best bet. Find one with whom you can form a good rapport. There are good options in NYC.
Take a look at this shirt from Ralph Lauren (http://www.ralphlauren.com/product/index.jsp?productId=84169576&cp=1760781.2004212&ab=tn_men_cs_dressshirts&parentPage=family
Notice how much easier the fabric falls on the back.
Your shirt looks like it needs much more room through the torso, and it looks (and I am NOT a shirtmaker, and I am a stylist, not a "designer" in the traditional sense, so my advice should be taken with considerably caution), as though the shoulder of the shape is just misaligned with yours. Also, the yoke seems to sit very low on your shirt, well past the "roll" of your shoulders.
Seriously, might be worth working with a custom shirtmaker, in person. The alternatives are to buy RTW. get something that fits well already, and then get it altered from there, or to go with a MTM outfit like Individualized Shirts offers (Epaulet www.epauletnewyork.com
) in NYC offers such a program, as does Drinkwaters in Cambridge MA (@Drinkwaters
). These are not "budget" options, but they are a little more affordable.
None of these options are likely to be inexpensive, of course. There's a price for everything.