To get height, you will need to pick one of the top branches that is weeping, and using wire, you will have to wire it up to make the next upright segment of trunk. After 18 months or so the branch wired to vertical will hold its position, maybe sooner. Remove wire if you notice it cutting in, then re-wire avoiding using the exact same grooves as previous wire.
Your trunk is at a perfect 90 degree to the soil level. When you repot you should put the tree on a slight angle, if you like up to a moderate angle. Dead arrow vertical is usually reserved for very formal upright designs. Weeping trees always have at least some slant to them.
