Question

"Why is it so taxing to care for my mother?  She is a sweet lady, yet I find caring for her and my family takes all the time that I have. I find myself getting irritable with her for just little things.  For instance, she has knick-knacks everywhere.  Since I am the housekeeper for her, I am forced to keep them all clean. Frankly, it takes more time than I have.  As you can see, I am a bit annoyed." 

Answer

You sound a bit overextended and tired, and you have every right to be. Raising a family and caring for a parent takes almost everyone "to the mat" at times. It is actually no surprise to me, not one bit.
 
You are overextended, a situation that most of us find ourselves in at some point in life. It is a very uncomfortable place to be for you. I completely understand and you are not imagining it.  
 
So, let me offer some advice. First, do what you must at your mother's home, but leave the unessential tasks alone. Let the dust on her knick-knacks lie. Dust is not much of a health hazard. If Mom wants a thorough house cleaning each week, and it is too much for you to handle, tell her, "No," or offer to help her hire a housekeeper. Do not let your mother or yourself guilt you into exhaustion. Give yourself a break.
 
If you have siblings, it is time to seek that break from them. If neither Mom nor siblings can afford it, seek some outside help. Realize that when we save our money it is for times like this. She will not be taking her money with her, and what good will it do you if your health is gone? A housekeeper once per week may just do the trick. A clean house does feel good for all involved.
 
I do not recommend telling your mother that her favorite things must go. Each one of those items will have some sentimental meaning for her. Unless she is hoarding everything that comes into her home (e.g., newspapers, cardboard, mail, etc.), and movement is restricted due to her decorations, removal may be difficult for her.
 
You seem to realize that it is not your mother's fault she needs assistance. Many, many older adults find themselves in this situation. Try your best to find the humor in it all, seek out others that can support you or share tips, and most of all, let anything go that you can.
 
Try your best to get enough sleep, eat three meals a day, exercise, play, and laugh. Balance is essential, even when it seems impossible. Schedule breaks as though they are as important as other tasks. I actually recommend a weekly scheduled night out, with no exception. It will be something to look forward to, a bit like an oasis for you.

I wish you the best.