You really need to understand the concept of SGA (Significant Gainful Activity which is $1090 per month.)

"To be eligible for disability benefits, a person must be unable to engage in substantial gainful activity (SGA)."

"Trial work period
After a person becomes eligible for disability benefits, the person may attempt to return to the work force. As an incentive, we provide a trial work period in which a beneficiary may have earnings and still collect benefits."

Underlined above is my emphasis.

https://www.socialsecurity.gov/oact/cola/sga.html

So long as your earnings remain under the SGA amount, you can pursue SSDI benefits.

The term I believe you were looking for is Unsuccessful Work Attempt (UWA). Links: https://secure.ssa.gov/poms.nsf/lnx/0411010145
https://secure.ssa.gov/poms.nsf/lnx/0424005001

You should probably discuss the idea of attempting to work as a sub with your psychiatrist. Are you sure your district would even use you as a sub at this point? Does your district have a policy regarding employees with severe mental impairments like Bipolar Disorder? I just spoke with someone that related that they were refused to be allowed to volunteer at their high school due to their BP. It would seem more appropriate to try and teach adults pt in evening classes at this point, which should also be less stressful. Or, if you really wish to explore something in the educational field, you could maybe try something like selling textbooks to school districts.

There are lots of unskilled jobs you might consider as well. You should probably contact your local Vocational Rehabilitation services and see if they might be able to help you.