As a big guy you can carry a full size pistol concealed. I have carried a 1911 for years.
You will have to modify your dress though. A loose fitting long tailed shirt unbuttoned works very well. Depending on were you live, the Hispanics have a shirt, I forget what they call it, which would fit the bill. In that culture these shirts are the equivalent of a sports jacket.
Do to my body structure (curved spine) I can carry either a 1911 or EAA Witness in the small of my back. The but fits into the curve and my shirt drapes over it.