As someone living with bipolar I especially like "Time heals almost everything, give it time" because god knows I've been through hard times I thought I couldn't come out of, but I always did

And I also like "Stop thinking too much" because when I'm in a state of mania I feel like like my mind is racing and won't slow down. "Stop thinking so too much" is obviously easier said than done, but none the less, it's good advice!