Hi. Sorry for the issues! I would try to help.
You can refuel the ship using clouds. Try refueling at the beginning of the level and you should have enough fuel for all islands.
You can also save some fuel by building momentum and then sliding the ship in correct direction (It takes time to slow don ship, but this movement is free in terms of fuel0
You can use RMB to suck in clouds. There are cloud generators in some levels
There is device on the front of the ship. You can shoot clouds there (using LMB) and it will refuel the ship