The Cup - Is it 1/2 Full or 1/2 Empty

I'm pondering how to think about my experience last night at the gym. After being banished off the treadmill by the physical therapist, I decided to give it a try. I did the 5k "lake loop" which, I gotta say, really treadmill people? I'm supposed to imagine myself running around a lake? Yeahh..thats a stretch. It took me 53 minutes to finish that 5k. I don't know weather to be pleased that I didn't die or pass out or pissed off that it took me 53 minutes. I'm not happy with that time. 45 minutes is my initial goal and I will not accept anything more than that in a real run.
As I pondered my goal of 45 minutes, I find myself wondering if I have to choose between practice and endurance or fat-burning weightloss? I know the evil machine will accomplish the fat-burning but I also know that I need to get my body used to running and the impact of running. My wonderful husband that he is, seems convinced that I can do both at the sametime. I'm doubtful about that one. I know my body cannot handle the 30 minute burn on the evil machine and then turn around to do the treadmill. He suggested doing a modified version of the 5k on those days that I do both.
Something I've learned about myself throughout this journey? I"m not much of a free-thinker and I enjoy plans. What I want? Is for someone to know my goals and give me a plan on how to get there. I need to evaluate my needs and abilities at the gym and figure out how to make this work.
You know what also came to my realization yesterday during my hellish 53 minutes? Is how much my journey is ever-evolving. I realize that that yes, while I enjoy plans, I realize they have to grow and move with you as you progress. I can appreciate that. When I started this journey, I never thought I would be sitting in my office, wishing I was out running. When I have a bad day (like today!) I really wished I could have hit the gym to clear my mind and lose myself in my music. THAT is something I can be proud of and count as the cup being half-full.