Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I've only played it briefly, but what you're talking about is likely stalling. Stalling isn't modeled very accurately in the game and is pretty forgiving. When your airspeed is too slow in an aircraft you don't have nearly as much control, things become sluggish relatively quickly as air speed drops. Part of that is also the nose having a tendency to drop.
throttle up or flaps? It's planes not helocopters, you need a minumum speed to stay airborne. If this is happening when your clawing for altitude to get to the bombers you can try flaps when you get the airspeed warning, stabilize to level flight, gain some speed and raise flaps, climb again when you have higher speed. Chasing high altitude bombers is hard for a lot of planes. Best with ME 109's and P-39s and their like.