Addpropforce to player?

[FlawlessHappiness]

You need to update to v1.3 to use SetPlayerFallDamageDisabled.

void BOOM(string &in asTimer)
{
AddTimer("", 6,"BOOM");
AddPlayerBodyForce(0, 0, 100000, true);
SetPlayerFallDamageDisabled(true);
}

Look at this timer.
Do you see, that you're adding another timer in it?

AddTimer("", 6,"BOOM");

You're saying, "When I call this timer, call it again in 6 seconds". And then it repeats.

"When I call this timer, call it again in 6 seconds"
"When I call this timer, call it again in 6 seconds"
"When I call this timer, call it again in 6 seconds"

And so on. All you have to do it remove the add timer.

void BOOM(string &in asTimer)
{
AddPlayerBodyForce(0, 0, 100000, true);
SetPlayerFallDamageDisabled(true);
}