While it’s rather 4 years than 2 
, that’s true.
But your current problems are not related to the OH version.
Seems you have a pretty strange setup, neither of this seems to happen on “today’s” Pis.
Have you considered moving to openHABian and install OH1 on top (for the time being) ?
Either way, consider adding a USB stick and move swap there as described here. Should give you some extra headroom.