Mom (81) has Stage 4 COPD and chronic back pain. What can be done for pain?

Rx for morphine didn't go well, now on methadone and losing cognitive abilities. On 3 liters O2 24/7. Norco was our go-to Rx for a couple years, but lost effect. Morphine prescribed caused stomach upset, chills and confusion. Doc changed it to Methadone, but over the last month since she was switched to these meds, she has really started to lose her reasoning and short term memory. She is remember things and thinking they happened the other day but in fact was a year or more ago. Vivid dreaming and she awakes, thinking things in her dreams really happened. Yesterday she thought she heard my brother (who lives cross country) and came out looking for him.

She has let me start doing her personal accounting and bill paying finally, as she is aware that her brain is not serving her well anymore. She is having trouble signing on to her electronic devices and distinguishing from email, text or phone calls (I suspect she may not be remembering her passwords or tremors make her enter them wrong). Her appetite is decreased, and she leeping a lot more, but also irregularly. She is also complaining of pain, saying the medicine doesn't help. Her bedroom is upstairs in the house, and she still can make it up and down ok, although slowly. She often comes down without her cannula on, and sometimes I go up and she isn't wearing is so I remind her to put it on.

Her cognitive abilities have declined considerably over the last 2 months, and I don't know if it's the meds or not enough O2 to her brain, or if she is developing Alzheimers, which her mother had. She does manage her meds ok and does log all over her medicines taken and the time in a little book, but I am growing more and more concerned that nothing seems to help her pain, and whether she needs more care than I can provide.

She will not qualify for medicaid for quite some time, yet there are not enough assets to put her in assisted living, as she refuses to spend the CD she is reserving for my brother when she passes. (Note, brother has gambling problem and filed BK twice) we have bailed him out of financial difficulty more than once, but no longer desire to enable him...he is also living with and caring for wife's mom in MIL's home).

I guess what I'm trying to figure out here is if there is something that can be done to help with her pain without putting her in a stupor, if it might be time for hosipice if this is the beginning of the end and I need to prepare myself.