Any tips on the SR-71A?

I've got the Alphasim Lockheed SR-71A Blackbird and need some tips on controlling it. Even at a low altitude (8,000 ft), it rises its nose then swirls around and stalls. I've read that it's service altitude is 85,000 ft but I can't even hit 10,000ft. I've had better luck with a freeware F-16 which my friend managed to get up to 92,000ft.

What's your indicated airspeed as you climb? I would suggest 300 KIAS.

I can't remember what my airspeed was as I was checking my altitude via Shift Z as the instruments aren't very easy to read from.

Thanks for the tip. I'll try it later on today.