proxy setup keeps changing when i add more profiles

i have been trying various proxies for some time but the process is pretty simple as long as i work with just a few profiles. however as i add more of them then the whole process becomes very complicated.

When i am setting up one profile then everything works out fine. the next one starts to have connectivity problems and the settings begin acting weird. some times cannot figure out whether the problem is with the proxy or the browser profile in general and might make a mistake somewhere while fixing some other issue.

I want to avoid switching between providers and changing my settings all the time. it would be better to have a clean system in which i have separate settings for each of my profiles and know exactly what connects to what.

does anyone have any experience with managing proxies for several profiles? what is your method to avoid inconsistencies?