There are at least three reasons why your credit score / rating will be reduced with your behaviours.

1. The number of hard inquiry will be too much.
2. The average length of all accounts will be too low.
3. The number of new accounts will be too high for the most recent period.

When you get your credit report, look at the "reason code" for scoring basis. Then you will likely see these listed as why your score was negatively affected.

If you are thinking about mortgage or car loan within the next 12 months... my advice is not to get any new credit until them so the accounts will settle down to increase the score. Because you might get these denied if you keep playing this card game.