Change Projectile speed after Spawning

Hello, as the title says i need to figure out how to change the projectile speed after the projectile is spawing or at least spawning with the amount of speed i want it to have.

Im trying to make a spear projectile, so by holding the left mouse button, the speed should increase and after releasing the mouse button, the projectile spawn with the custom speed.

This is my setup:

Sadly it doent work like i want it to, any clue whats wrong or what im missing there?

After releasing the mouse button i made a small delay before “stopping” the timeline so i can make sure the float value doesnt get lost.

Hope you guys can help me there

*EDIT: The projectile movement has the “default” values exept for rotation follows velocity is checked