Hi all , wondering if anyone can help me?

I have a my 98 wrx . Car is stock.

Last night while driving down mandurah i was in 4th gear doing 90 and speed limit increase to 110 so i put foot down pretty hard to get up to speed limit then overtake a car and my wrx cuts out forabout a second then keeps going.

I tryed various things like rolling it on in 1st, 2nd, 3rd nothing only rolling it on hard in 4th.

Scares shit out me while its accelerating nice without any notice cuts out for a second causing car to jolt

Any help much appreciated

MArc