How much are you doing for elderly parents?

I've posted this before a few years back, obv still an issue for me.  But how much is too much?  I try and dedicate one day a week to take them shopping, chemist, general stuff, and then am in daily contact, and then am asked every other day "are you around today"? I also have stuff of my own to do, but end up taking them on other errands probably at least 3 days a week.  There is public transport very close to their home and they also get half price taxi fares due to ill health. (mainly just old age problems).

Don't get my wrong I love them dearly but I find they become very negative as they age, everything is a problem or hard work.  They don't seem to want to make life easier for themselves, instead complain about how hard things are with not driving, relying on others etc.  It becomes that it gets you down to be around that negativity.  

 

Any advice appreciated!