How often do you change tactics

How often do you change your tactics? I find that I can use my tactics and they’ll work for like 6-8 games and I’d destroy teams then after that we go on a losing streak and they tell me to change my style, which leads to me chopping and changing all the time instead of staying with a particular tactic for a whole season that I can build on. It’s always by the January mark that everything just goes wrong and I fall down and the table