Peli,
To comment usefully on this, I think I need to know the goals of your training.
I used to have a turbo and did a couple of turbo sessions, but only because it meant I could be at home and not very far from the wife's beck and call in training for my coast to coast.
After that, I couldn't really see the point in turbo training - not for what I was doing. I wasn't racing, after all.
In general, if I want to improve my fitness, I just get on the bike. The more miles I manage to do average in a week, the more miles I can comfortably do in an epic when called upon and the faster I can do them.
I get natural intervals from hills, sprinting through junctions to clear them as quickly as possible, racing past the odd cycle commuter and so on. On a day when I'm feeling a bit rough, it's easy to ignore those little challenges and just ride at a steady pace.
I don't train. Yet cycling home from the City Centre on Saturday I got talking to a club cyclist on the way home from seeing his cycling coach. We rode competitively and after a while he piped up, "Do you race?".
If you are struggling to get out on your bike more, use the turbo, but instead of completing a training DVD aimed at racing cyclists and ironmen, why not just pootle on it whilst watching your favourite soaps? If you are drowning out the sound, you know you are putting effort into it!!!
And the key really is to gradually build it up. I've been cycling with not significant breaks for five years. I think if I was to really train hard, run myself down, and then continue I would set myself back months, even years.
It sounds like you have a decent base level of fitness already. How is your pedalling technique?
I understand how you might perceive that you are not very fit, Maffie does the same. Yet she did 55 miles with me on the Tandem on Sunday, the furthest she has ever been. Even at the end of the ride, she was chomping the bit at the foot of every hill and we even climbed some of the short sharp ones in the large chain ring!!!
Finally, Listen to your partner. He probably can see better than you when you should rest.
Good luck Peli.