Correction: You have only lost 4 in a row. I wouldn't count scrimmage losses as losses as that should be a game when scrubs are playing to keep GS up.
Of the games you did lose, your team ratings are significantly worse than the teams you played against. Your team simply just wasn't good enough to beat them. Tactics only take you so far but a superior team with good skills can still beat you even if you set perfect tactics.
If you want a short term fix, then spend some cash and buy some better players off the transfer market. Otherwise for a long term approach, develop a good training regime and train your young players.