It sounds like you are taking the extra precautions needed to look after yourself and prevent contraction anything... definitely continue to wear gloves and the mask, wash your hands really good after, and cleaning the litter box frequently is best practice as it decreases the chance of toxoplasmosis spores from forming.... i read a recent post from a vet student saying that the spores can form in as little as 12 hours so clean twice a day would be by far the safest! Also because you have had a cat for many years there is a good chance that you may have already been exposed in the past which means your probably okay BUT unless your Dr has tested you to confirm this you cant assume that you are.... but i do agree if you can get someone else to change the litter then by all means thats the safest route :) OH and the same precautions need to be used when gardening as well as the garden tends to be one big litter box for kitties :)
I have indoor cats too and u was told nit to change the box. I make the hubby do it. I don't think it matters if they are outside or in.
Cats poo really does contain nasty bugs and illnesses. Is there no one else you could get to do it for you..just to be on the safe side. If not I don't know If mask and gloves are cautious enough or if that's still unsafe. Hope someone can shed some nlight for you x