i love coffee

u can try by reaching out live agent or live chat of uscis 
no email https://www.uscis.gov/tools/meet-emma-our-virtual-assistant
approval is up to USCIS

Google "expedite USCIS" to get all the info.

Normally the urgent reason needs to be the USC’s, not the beneficiary’s.

Yes.   But again, expedites are much more likely to be approved if it is to benefit the USC petitioner, NOT beneficiary.
 
Most are denied.   No harm in trying.   You’ll need documentation/evidence to back up the reason for your request.

From your April 6th post your case is at embassy waiting for u to schedule interview/that's about the best it can be
 
and u want to come to the US for medical reasons with no health insurance here or US dr already?
Just to let u understand ,  unless u go to an emergency room,  u may wait months to get into a dr for an appointment 
do u have any idea of how much this will cost????
 

You can request an expedite.  The result will be that if approved, they will let you schedule an interview at the next available open spot.  They will not cancel someone else's interview to accommodate.
 
Which is basically the stage you are at now - trying to schedule the interview.   Therefore, trying to expedite at this stage is pointless.
 
Better option is to join a whatsapp or facebook group of K1 hopefuls for your country to be informed of new openings on the calendar.