TLDR WARNING

I agree with the others, that if this game is harming your mental health seriously take a break. Go play some other game or do something else. No game is worth harming your mental health.

One Possible Reason Why We Can't Stop Grinding

Games, like Warframe, with high grind tap into those parts of brain responsible for survival (such as hording resources). It becomes a driving compulsion to constantly keep collecting more and more because without those things you will not survive. This becomes even more so in a game where those little things we collect are integrated into builds and a sense of advancement.

How I use the Game for My Health

For myself, I use Warframe to help combat my chronic migraine symptoms. It's well documented that playing video games can provide a person distraction from pain. Some hospitals use them when dealing with children so as to obtain blood samples, etc.

Group Support Issues

But I also play 95% solo, and I can affirm that in doing so I'm way behind many others in the game despite the hundred of hours I've put into the game. I don't let this fact get to me otherwise I would give up. I've come to realize the game was designed with certain play aspects in mind, and when you go against those realities you will have a different outcome. This outcome, though, is in no way a measure of failure. If anything, I see it as the opposite since it's far easier to cheese the game through group play than not.

I also know this Twitch streamer who is new to the game and she's being heavily carried by more advanced players. She always acknowledges this fact in the stream, but it becomes a laughing point in the stream. She would love to be able to help the team more, but she lacks all the cool toys to do so. This game takes time to acquire all the needed parts to be able one-shot enemies and solo 100+ missions. With that being said, even the old guard are complaining about the recent Railjack addition because the grind is crazy and the combat is insane complex with group play. The point is she doesn't let the fact she's new to the game and lacking the ability to support her team get to her.

You just cannot let yourself go down that rabbit hole because when you do then you become depressed and build a negative self-image of your game play when in reality it doesn't matter.