Welcome to WOWP.
You say the game is unplayable ?
What kind of ping and FPS are you having ?
Or are you having computer related issues ?
Or is it your lack of knowledge about the play-ability of the game itself ?
The next tier plane will not make you better or increase your odds of winning.
There is no reason to rush up the tiers. Rushing up to the jets will only frustrate you with more
of a losing streak than you already have.
If you regroup and fly in the lower tiers to learn more about the fundamentals and get good in the lower tier bi-planes
then you can move on to the next tier.
If it is computer/ internet related issues then all I can say is either do not play or get a better computer.
It is a difficult game to play with a low grade computer/ internet issues but still can be done
IF YOU LEARN THE BASICS IN THE LOWER TIERS.
Here are some computer/ internet related issue video's to show you that
IF YOU LEARN THE BASICS IN THE LOWER TIERS YOU CAN START DOING BETTER IN THE HIGHER TIERS.