Constant changes of tactics doesn't help. Don't test your tactic in friendly games - absolutely pointless.
Check some of the tactics here, at least how they are built if you don't want to use them. I found it hard to use one tactic through out the season so I have three to choose depends on circumstances, home away strong weak opponent.
The other thing is if you keep loosing games and you keep changing tactics - you won't get anything apart from more loses.
Two approaches possible in general. Either you build a tactic for the players you have, or you build a tactic and buy players for it. Your choice.