Wishing you a speedy recovery!
Easiest way to get to the home page for me is to click on the blue house in the upper left corner, which 'floats' and is always available.
The reply box is below the post you want to reply to, although you may need to scroll down a bit to get to it. When done with your reply, remember to hit the green 'finished' button below the reply box to actually post it.