Usually I train every other day, but there are times when circumstances don't allow me to follow this schedule. I really feel like I have lost the chance to get better. Could I sort of compensate for the lost day by training the next days in a row?
That might work, but make sure not to be missing your rest, because it is crucial to have enough rest. This will help prevent side effects, and it will contribute to muscle growth.
There are no set rules on how often or when you should train. I think most people are actually more guilty of not taking the extra day off when they need it vs missing a day here and there. In the end, just train when you can.