Umm, have you played to the end that I pressume, unfortunately there is no way to save Eric from... 'that end' :') Thank you for supporting our game though, means a lot :D
Yes, you can still get the good ending as long as you've seen their last romantic event (Usually a confession) and you've maxed a certain stat. Example, you will unlock Liz's good ending by making your deception at least 120 (Deceiving). You can see here for more info https://gameplay.tips/guides/1071-amplitude.html