Problem With Take-Off Battle Of Britain II: Wings Of Victory

[Roger69]

I have problem with take-off. Sometimes even I can't go to air. But when I am I have big problems and often crash. Plane is unstable, heavy and like doesn't have enough power. I can't go higher and after 2 minutes in air plane is more and more unstable and crash.
I am amateur and I am not familiar with other flying simulators and plane equipment, controls and skills.

What I am doing wrong?

This is how it looks:
Start game -> Instant Action -> Basic Training (Take-off, Scenario) -> Spitfire1A (54 Squadron, Patrol, Trumpet, Bob) -> Fly

First I put 60 Rpm then I click both comma & dot keys to release breaks from left and right wheel then I put 80, 90 rpm then max rpm.
When front starting goes down I am pulling the tail, when still on the ground plane is unstable and often falling to left or right side but I am carefully correcting plane position using left or right wheel brake and joystick. When plane finally goes to air is very unstable.
I am hiding the wheels using G key then trying go more up but I can't and plane have like less and less power and is more unstable and crash.
Please help.