Are you saying it sprays across the length of the tub and sprays the opposite end wall of the tub? If so, can you rotate the bracket on the slidebar so the head points at a lower angle? Or change the spray pattern?

If the wide spray pattern is causing it to spray the long wall of the tub, then you can adjust the spray pattern on the head if it is indeed adjustable, or you can get a new head. If you get a new head, take your old one with you when you go shopping to make sure the hose/bracket connections are compatible.

We had a similar issue with a wall mounted hand held shower head. We ended up replacing the attachment at the wall. In your case, you need a a replacement for the way your hand held attaches to the bar that allows the head to be pointed elsewhere than straight ahead. Here is one from HD that's kind of ugly but the right idea.

Here is a link that might be useful: Wall Bar Mount for Hand Held Shower

Duh and thank you to Mongo ! So simple a solution to a problem that vexed me for a long time . Sometimes the answer is right in front and so simple one doesn't see it .
Salbwil