I'm in the same situation.. had been shoting right handed for many years before someone pointed out that my left eye was dominant.
With rifles, i always managed to sight with my right eye... after all these years my left eye is used to closing, but i did struggle with match pistol, and ended up using a blind over the left eye.
When shooting FB pistol (2 handed), I've adjusted my position over the years and now bring the pistol more across my body to use the left eye.
Things have got worse over the last year, and I've now been diagnosed with cataracts forming on my right eye!
I did try shooting left handed a few weeks ago, it just felt so wrong..!