I have had diverticulosis for about 12 years, and I was exactly the same as the OP - couldn't even consider leaving the house until around 11.00am. As you can imagine, this was a huge problem when I was still working - due to the problem I was allowed a parking pass for the extremely limited car park at work, so generally managed to make it to work (about a 20-30 minute journey). There were some days, though, when I couldn't leave the house and would work from home.
However, since having surgery 18 months ago for another bowel problem, this problem has largely gone away, thank heavens! I still have the odd day when I can't leave the house, but it's really very rare now.
I used to take Loperamide regularly - tbh I couldn't have managed any kind of normal life without it. Unlike others' doctors, mine told me it was perfectly safe; that all it did was slow down the transit of waste, giving the gut a chance to absorb more liquid, thereby firming up the waste before it reached the exit. When I asked him why the packaging warned to take for no longer than 2 weeks, and see your GP if things hadn't improved, he explained that was because any change in bowel habits for a protracted period should be investigated. However, in my case, all the investigations had taken place and therefore there was no harm in continuing to take it.
Now, with so many posters saying they were warned against taking it, I'm wondering whether this was bad advice