Why can't I take my mom home when I'm the trustee and executrix?

You need legal advice.

Usually a later POA cancels out all earlier ones.

Assets MUST be used for the care of the principal. If you sister is breaking the law and stealing assets she needs to be stopped. Sleeping with cops won't protect her.

Get a lawyer.

Go back to the attorney who drew up your POA and, if you have a copy of it, your sister's POA and take advice. Clearly there has been a major breakdown of communication somewhere. I wouldn't try to sort it out on my own if I were you. And try not to say anything to anybody that you might later regret.

I'm very sorry for your mother's distress, which must be terribly upsetting for you. Try not to panic. Take deep breaths and get good advice.

Even if your mom was mentally competent and knew that she was giving your sister POA in February, your sister has no right to do things against the wishes of your mom as long as your mom is mentally competent. Your mom can revoke the POA she give Sister. You need to contact the attorney who prepared your POA immediately with all the information you have.

My mother had been living alone. She could still, but I could care for her. I am 60, retired, same as husband. I have POA, health POA, sisters are 2 months newer. I am succ trustee of her trust and executrix, all prepared by Attny 12-23-16. Sis POA is dated feb 2017
Sis has been removing assets out of trust, putting her name on each. Mother has excess of $2M. Sis only cares about money. She recently cancelled her phone 4 times, filed a R.O. On me to prevent any talking to mom or other 2 siblings, Judge threw it out. Our pops are same, why does her word go? I mean, besides she has slept with every cop?
My dad died 5 yrs ago, she lied on paperwork so no other sibling was notified. She "gave" me a old pair of his sweatpants to "remember" him by....of course not the truck or other $ things. She always hated my mom, until she realized her worth, which I always knew as she relied on me for keeping straight. I have had POA since 2001.

Do you really think you can do this 24/7? While your heart is in the right place, you may be overestimating your ability to do what takes three shifts of nurses to do. Try to calm down, because a restraining order will keep you from seeing her at all.
Assets: a court appointed Guardian is expected to sell the house and use the Trust money for your mother's care. That is pretty standard. It might help for you to sit down with an attorney and know what you can and cannot do.

How long has your mother in "a home"? Nursing home? Assisted living? Memory care? Where did she live and who was taking care of her before she went to a care center?

Who has healthcare power of attorney? Financial power of attorney?

Is it just you and your sister or do you have other siblings?

What can you do so that you may see your mother? For example, could you visit with her in a common room (rather than her room)?

Do you work? Have a husband? Children? Do you have any experience caring for someone with dementia? Does your mother have the financial means to pay for in-home help?

I am sorry to ask so many questions, but understanding the background will help us provide for relevant comments.