In Photos I cannot connect my Facebook account

hi...i have updated to the latest version of Yosemite, which included a change from iPhoto to Photos. it seems to work okay except for when i try to share pictures from Photos to Facebook.

it directs me to add my Facebook account on Internet Accounts in System Preferences. I have attempted to add my Facebook account at least a dozen times and failed each time.

i enter my email and password for Facebook and i get a box asking me to wait for a code to be texted to me to enter instead of my FB password. the code arrives, i enter it in the password box, and i get the same message in red: 'unable to verify account name or password'.

then i receive messages on Facebook saying that an 'unrecognized' browser is attempting to log in to my account (even though i've 'approved' it as 'recognized' by me multiple times now).

so i cannot connect with Facebook via my MacBook Pro (only through my iPhone).

any suggestions?

thanks.