I'm terribly sorry to hear your situation. I can't understand how it must feel. I hope these 2 years have given you time to heal a bit, because I know those scars don't ever fade away.
Regarding the game, the game itself doesn't have a dark atmosphere to it, it's generally a good environment, but embraces the theme of depression and suicide.
The game has a positive vibe to it, but this latest chapter has a bit of a dark cloud over it. I'd say play it for the story, but if you feel like you can't handle it, don't, the game itself in this chapter warns you to skip some scenes in case you are not in a good place in your life.
If you decide to play it, good luck and I hope you enjoy it.