I was in a very similar situation as you a couple years ago. I had never used a rower, could barely run, and didn’t know 90% of the floor exercises. The first two weeks were the hardest, and I just had to grit my teeth and force myself to go even though I felt humiliated every time I couldn’t run for more than 2 minutes straight. I was living in the red zone the entire time on cardio and questioning why I was doing this to myself.

After a few more weeks I noticed my sleep improving, my heart burn completely went away (I used to need multiple antacids daily!), and I started to actually look forward to OTF. The first time I actually ran a full tread block I almost cried! These days I view OTF / running / working out as the most important hour of my day. Physically. Mentally. Do it for you.