How long do you think you need to give it become aware of what you need vs a temporary state of mind? Was in my last position for 18 months, and the one before

How long do you think you need to give it become aware of what you need vs a temporary state of mind? Was in my last position for 18 months, and the one before for 3 1/2 years, but now after only a couple of months am back to where I was feeling toward the end of both of those places. It is a great company, and a fantastic opportunity, but do mentally seem to be struggling.