At the broadest level, what you are describing already exists. It's called a "pharmacy" here in the US, and generally includes both a selection of medicines with an acceptinly low risk of harm and diagnostic equipment that can be accurately used without formal training.

For a more electronic example, there have been numerous attempts to augment what used to be a purely manual profession over the years. Several of these are adapted and incredibly useful -- any doctor I see can view a shareable electronic record of my treatment, prescriptions are electronically transmitted to a pharmacy, and there are even custom interfaces for electronically checking standards of treatment or insurance coverage.

What you won't find in general availability are "virtual doctors" that combine an inquiry as to your problem and an application of potential solutions, because humans are absurdly complicated ongoing chemical reactions whose communication is absurdly unreliable.

Or, to put it another way: a lot of people are trying, but it's a hell of a lot harder than you imagine.