[Barrin92]

You're not at all too old to switch your career. In fact there is no such thing, but given that you have invested a lot of time and presumably money into your medical education do not throw that away. Finish your education, make some money, and if you're in a financially stable situation try to look for some programming opportunities.

As far as the ageism within 'tech culture' goes that has been brought up in a few posts, you don't need to work in the startup sector to work as a software engineer. Almost every large industry today hires software engineers, and most of them do not share this bizarre obsession with youth that you have in the valley. Maybe not the perfect site to point it out but Paul Graham says a lot of silly things, that only apply to a very small, geographically limited group of people.