Then go to play some sport and get fun. The answer is easy.
That is the magic answer to your situation.
But the reality is that it's not only your situation. It's many of us. Dig through the archives of the lifter profile stories and you'll see that the successful ones are the ones that are consistent. That's it. Consistent.
Each and every one of us has that period of the program where a single lift is or all of the lifts are soul crushing. It all comes down to programming and/or recovery. Short of a broken bone, a break is rarely the answer.
Consider logging your workouts over in the training logs forum. Sometimes that's the best way for all of us to identify an issue. And believe it or not, everyone is generally supportive.
Keep at it!
Then go to play some sport and get fun. The answer is easy.
Have you considered hiring a coach?
There was a period where it helped me maintain consistency. They prescribe the work, and you just do it. If you’re not good at being disciplined, and accountable to yourself it can help.
It helps to have a goal. 3 plate squat, 4 plate deadlift, etc.
Stress has a significant impact on feelings of pleasure and motivation. Lifting weights has long-term benefits both physically and mentally, but they are still acute stress events. Your worries are psychological stress, most likely chronic. People with bipolar disorder are especially vulnerable to stress. I guess stress management should be a large part of your training to avoid feeling crushed.