Is there a cure for this? Will it expire?
Sorry, you will have to live with it for the rest of that game. The best bet for you now is to just remove the engines and you should have enough passive bonuses to hit a speed of 5.
Start putting starports on all planets to save on time to get ships to places by building closer to the front.
Also, use your own planets as slingshots to gain another 2 parsecs of movement. If you are going near a planet, enter it's orbit (costs 0 movement to enter orbit) then switch the exit parsec for the planet to the direction your headed, then exit the planet (costs 0 movement). You just increased your speed by 40% by doing this. If used in a system with many planets, you can have tons of movement points to add.
