I have a "Breakdown day" 2 or 3 times a year. I know EXACTLY what you felt like and what you experienced. These emotional breakdowns always follow an episode of "not being able to do something anymore", just like you described. It is followed by hours or even days of deep depression, frustration, hopelessness and anger.
Somehow, thankfully it always passes. I usually figure out a compensation or a new technique. And then I feel pretty good for a while. Then down the road the compensation no longer works and I have another bad emotional episode.
Do you have a lift recliner? They are worth every penny. Hopefully they are available in South Africa. I purchased one when I could no longer get up from our sofa about 3 years ago. I also have an UpEasy portable seat cushion to take places with me. You should take a look at both of these items.
Lately however I've been struggling a bit to get up even from my lift recliner and my toilet riser. This has me worried but I'm trying to think ahead for a solution before that awful day comes when I can't.
Sorry I can't offer more to solve your problem. All I can offer is a little advice and an empathetic ear to vent to. Hang in there!