Low Supply

So, I have been back at work for almost a month now. I pump while at work and BF when I am with my son. I struggle to have sufficient time to pump. I pump for about 12min, but by the time I've set up and cleaned up its been half an hour. I'm a teacher so I can't be away from my class for too long. It's a constant struggle to try to keep up my supply bcus my son eats so much. In an entire work day I am only able to pump 8-10oz. My son eats way more than that within those 9 hrs that I am gone. I just started supplamenting. The pediatrician said to mix 2oz of breast milk with 2oz of formula. So far he seems to be taking it without a problem. So my question is, should I just let my supply dry out or should I just continue to pump no matter the amount so that i can continue to BF while at home. Any advice or past experiences are welcome. FTM here. I know fed is best but part of me feels kind of guilty for not trying harder to keep my supply up. But the other half of me kind of appreciates this deminish. As an FYI I do not plan on BF past the year, my plan is to go up to about 9 months. That's if my body can keep up. 👀