My trainer calls that first feeling the "oh sh*t" feeling and that pretty much everyone has it at the beginning of a ride or other effort, and you just warm up as gently as you can and get past it. I call it the "whose big idea was this anyway" feeling. Warming up slowly is really important but kind of hard on a bike. I'm a beginner, too, and it takes effort to keep going forward !

I also don't love riding with my DH (yet) - he tries not to push me, but sometimes he "nudges" and I don't want nudging. He's much fitter than I am, so when we ride, I am working my butt off, fitter than I've ever been, and STILL lagging while he's flitting off ahead. I really need my ride to be about having a feeling of accomplishment, not another situation in my life where I'm sure I'm not good enough.

But Joyfulgirl, you are doing GREAT! Just be proud of yourself, and the gains are going to come, faster than you think. There's probably already a road bike out there with your name on it!