I never have more than two cameras ready to go at a time. I don't want too much film sitting around. Sitting in the darkroom waiting for processing is OK, but sitting in the camera unused isn't what it's for. If you have lots of film to use, that's helpful too. I've got half a freezer full. I don't mind pulling out a pro-pack and breaking into it. I stocked up incase the kodak bankruptcy went bad for us. If I only had a couple rolls, I'd be hesitant to use it as well.

I mostly use one film too; tmax 400, as it's fine enough grain to be a replacement for slower film in normal conditions, and sensitive enough for lower light conditions. Sticking with one film will help you get the look you want as you learn how it handles scenes and colors. Other people might be fine with a traditionally grained 400 film; plenty of choices, but you should settle on a choice at some point if you want more quality shots per roll.

I'd support the suggestions to shoot at least a roll per event / outing. I shot 1 roll of 120 during a 1/3 mile walk the other day... I expect at least two quality photos worth printing per roll. Sometimes I have 5-6, sometimes 1.

Blasphemous suggestion; shoot digital for a little while to get over the hesitation to press the shutter. You can get lots of nicely made expiremental photos of excellent composition, but lacking the style/aesthetic/range of analog. Still a good learning experience. When I use digital, I shoot more than analog, but less than the people brought up on digital who will spend the whole night "editing" because they shot too much.