Hi Rita
When I shower on non-change days I just shower as normal and get out and towel dry my bag along with the rest of me. The wafer remains a tiny bit wet around the edges but body heat soon takes care of that :) On change days, I take everything off (I wear a one piece bag) and let the water run over my stoma to get it nice and clean. If Harriet (my stoma) outputs while I'm in the shower, it all goes down the drain anyway. You can clean the shower out with bleach afterwards if you want to.
When swimming, I just wear a one piece bathing suit with either a pattern or splash of colour over my stoma site. That disguises any slight bulge which may be there and never, in 32 years, has anyone commented they can see my bag under my bathers.
In time, you'll get back to most of the clothes you used to wear. In my teens, I used to wear the tightest jeans imaginable and no one could tell I had a bag. Yes, it would fill up, but I'd just go to the loo to empty it, no big deal really! I wear my bag at an angle towards my groin area so it doesn't hang down my leg. That way it's less noticeable as it fills up because it's not all on one side. I find it makes it easier to empty my bag while sitting down on the loo with my bag angled this way - just aim between my legs :)
The night drainage bags are for those with urostomies. They are not designed for and won't work for those of us with colostomies and ileostomies. Perhaps you could try switching to a bigger bag at night (if you wear a two piece bag) to save you getting up and emptying all the time?
Just a bit more advice too. Please, please try and change your bag yourself without hubby's assistance (unless, of course, you have a physical disability which prevents this). You CAN do it :) I was doing it all by myself at 10 years of age so it's not that hard once you get used to it. It's a BIG step towards accepting your ostomy and dealing with it. Have your husband there for support for the first couple of times, but do please try and do it for yourself. You will be nervous but you CAN do it :)
Take care and good luck.