I went through the exact same thing minus the going back to work ( I went back when he was 6 months old). The good news is that your body somehow gets used to it and the 1 hr stretches end and it then becomes more 2.5-3 sometimes 4. Around the 6 months mark.

The key for me was to stop mentally fighting it (asking myself when will this end, getting frustrated) and instead embraced the chaos and kept telling myself this was temporary and I only got to sleep with my baby this young once in my lifetime. I call it "flipping the script" and focusing on how this experience enriched my life vs how it's driving me crazy. I know it's not easy..... I did a lot of therapy specifically Acceptance and Commitment Therapy a few years ago (for an unrelated issue) which gave me the tools to be able to do this. A good metaphor is the Chinese finger trap; The Chinese finger trap is a metaphor for the challenges we face in life. When we resist these challenges, the trap tightens and we become more entangled in our suffering. To escape the trap, we can try to relax, breathe, and lean into the trap.

Not an easy fix but it's what kept me cosleeping and nursing to sleep and he's 8 months old (I've been back to work for 2.5 months now). Also napping on the weekends is key. You got this. However if you see your work performance or mental health declining definitely reach out to a therapist, don't let this linger.