Thanks for the comment :)
Honestly, it probably took me about a solid year to completely get use to my c-leg. And you know, for folks like you and me who have never had a completely normal leg, it's completely different from anything we've ever had before. And especially you having had the total knee for a good decade+ compared to me, I think it's totally understandable that it would take longer to get use to the c-leg that it took me. And I completely understand your frustration with it, I know I was frustrated in the beginning getting use to everything, and it's even more frustrating when you just don't feel totally confident in yourself or your ability to move around.
For me, once I switched to the c-leg I didn't go back to my total knee. I've been on my c-leg for probably about 2 and half years now, and have not taken another step with my total knee since. I still have it to fall back on in case of emergency, but I've used my c-leg ever since. And I think that can be helpful, not switching back and forth between two very different knees. They say practice makes perfect, and I think being able to be consistent with using the same leg can be helpful. I know I've also been very fortunate to have some wonderful prosthetists working on my legs throughout the years. So beyond keep practicing, I would recommend talking to your prosthetist, there might be some slight tweaks they can make that will help you feel more comfortable with it. I was also very fortunate to be able to be in physical therapy for the first several months when I made the switch, so if you have the resources available I would definitely recommend giving that a try. It will give you a place to sort test yourself, and push your limits without feeling like you're completely alone, because there's someone there to catch you if start to go down, and there's parallel bars so you can catch yourself. Plus, I know for me, the way I walked with the total knee was not really a good way to walk with the c-leg, so I had to basically learn a new gait, so having that physical therapist who was able to tell me what I was doing wrong, and how to correct myself was very helpful.
And I've totally just written you a novel, but hopefully there will be something useful in there ;)
It was challenging, and difficult, but I really do love my c-leg. I am proof positive that you can go from long term use of a total knee to a c-leg! ;) If I can do it, you can do it for sure! :)