Glad to hear from you again.

May I suggest either raising your computer desk to some 90 cm high (so you can stand and work on the computer) or get a tablet (so you can move about and change your posture while you work on Internet)?

You and I know (as we grow older ;-) sitting for a long time is not really good for us (or anyone). And by not sitting down in front of a computer, we invite more interruptions which keep our mind 'active' too. ;-)