Solutions for a broke teacher

I am a new grad teacher and I love my job. However, I am struggling immensely to find appropriate, comfortable clothes that are also affordable and sustainable. I have basically been cycling through the same 4 shirts that meet this criteria that I had from college.

Most of my coworkers buy their clothes from SHEIN or other fast fashion stores. I’ve tried thrifting, but it’s just too time consuming for my schedule and it’s pretty impossible to find things that meet this criteria anyways.

Any suggestions or advice would be greatly appreciated.