Can someone tell me how I should handle my work situation?

I would contact the Los Angeles Care Counseling Department of Alzheimer's Los Angeles, who provide counseling services by e-mail, telephone and/or in person free-of-charge, with planning, problem solving as well as caregiving training

I don't know if FMLA's are all the same or vary company to company but both of my brothers have them (both airline pilots) for our mom and get them renewed yearly with no issues, In fact one brother who actually uses his the least (lives furthest away) is the senior captain at his domain (the airport he flies out of) so not easy to replace but his company has been very understanding and helpful in navigating him through the FMLA and using it. The first time it came into play was during her heart surgery when he came last minute, he had never applied or used the FMLA and it was his scheduler who refereed him to the person to do that with who then put him on leave without it being done and enabled him to come east for as long as needed and do the paperwork while he was here, later when the dust settled a bit. I remember getting the doctor to sign it when she was being discharged. My other brother who lives closest to mom uses his all the time, I feel terrible about that but it comes in handy yes for doctors appointments though we tend to schedule those around his but more often for the little emergencies that pop up all the time, much the way you do I'm sure. But based on the way both of their FMLA's seem to work I have a couple thought's for you.

First know your right's, your company offers an FMLA and that means they need to honor it, stick by it's written parameters at least. It would be nice and probably better for everyone if your supervisor not only understood the purpose of the FMLA as written but the need and had some understanding of what you are dealing with, he or she obviously does not and doesn't have any interest in trying too. That's unfortunate but probably not unusual, I imagine most people who have never been a caregiver for aging LO or close to an Alzheimer patient want to be caring but in the work environment all they see is you coming and going as you please. It's hard to associate that with what you are doing instead of being at the office and have no conception that most of the time you would much rather be dealing with work and the office than home attending to the current crisis. They have no idea the mental and physical exhaustion, much like someone with a long term illness everyone is attentive and sympathetic at first when things are in the initial "crisis" stage but tend to forget as time goes on and assume "the worst is over", they aren't trying or meaning to be unsupportive or insensitive it's just inexperience I guess. Probably similar in your office so you may need to make the attempt to help them understand without loosing your cool. Putting in the extra effort to make sure your work is done and it isn't as disrupting from the accomplishment perspective of your employer will help too. Funny thing, my son was a high level ski racer and as a sophomore went off to a winter term ski academy, their students followed the home schools curriculum with tutors to teach the information but at his level he traveled so much he was mostly doing the work on his own, he discovered how much wasted time there was in a school day because he was able to achieve honor roll doing the lions share of his work the week before going back to his home school and turning it all in. My point being you may find you learn to budget your time and work smarter both at your employment and at home out of pure necessity and it might be harder for your supervisor to complain if you are still getting all your work done well. But try sharing some of the day to day mini crisis or even gifts (I took Mom out for a drive last night and it really seemed to calm her down, well worth the effort of getting her to the car!) but not in a complaining way. When you come in late or leave early let your supervisor or desk mate know why, give them a glimpse.

I agree with everyone who notes:  FMLA is your right!  It is government mandated and you can visit with your HR representative regarding your company's view on FMLA and HR's ability to intervene with your supervisor/co-workers if they do not respect the policy.  I have a copy of my signed FMLA hanging in my desk area for all to see. Whenever I feel someone has a problem with my absence regarding the needs of my parents I say:  "I'm sorry you feel putting my family before my job is irritating for you, but I love my parents and they deserve my help."  Do not be bullied!  After all...do you want to be remembered as a loving caregiver or as an unappreciated employee?