lbs=local bike store. Smaller in some wise better, mech, not sales.
19 inch mtb standover the toptube? = big..way big?
I'm 5-9,10? 16 inch standover, 21 inch toptube =wayy long stem.

Also, the seat needs to be less than correct 'road' geometry, the seat can be very important to putting the leg muscle\knee into the cranks, but mtb are for bumps etc, and a bit of clearance is needed. Ow.


Putting the seat foreward on the rails (the seat bars that attach to the seat post) can bring you foreward and onto the pedal.

Fitting is important -a cheap bike ..well no, and no $200 bar upgrades.
Get pics.
For $400 you could ride a nice bike out the door of a shop.

tell more...yes I ride uphill sitting down when I can -the weight keeps the tire from displacing the pepples if loose pack.

You don't need a longer stem if as you say -feel stretched over, short stem\ riser bars pulled back a little?