My U-IC is much simpler than yours as I tend to empty.
I assume you are working with you MD regarding medications for retention and they are not working?
Over the last couple of decades there has been several improvements regarding catheter surface finishing and pre lubrication. Likely worth a detailed discussion regarding what is available, specifically for females, with your MD. Sadly, the knowledge level at local and chain drug stores as come to a low point of; "what was prescribed" we will will order that for you.
Regarding your diapers, consider upgrading to a higher-capacity, premium diaper from (US based) Northshore diapers as they have an excellent customer service group that will help you define the diapers you should consider and they will provide you samples. You really want to target a night time diaper that will support you needs for the entire night!
NOTE: I am a big believer in maintaining a journal that follows your releases and some idea of volume. I use their Mega Max because I really dislike low capacity cased leaks, especially at night. Your daytime choice will clearly follow the number of daytime releases and volume. I am also a big believer in using plastic pants as yet another line of protection against leaks. Northshore's Trifecta Pant is an excellent product.