One problem I can see is that your current stem is fairly short. Most adjustables are quite long. Or at least longer than your current stem. The extra length will open up the cockpit which will cancel out some of the rise in the bars. It'll also change the way you ride the bike off road by moving you more forward. This makes it harder to get your weight back for descents and for kicking out the front going off small jumps.

So a lot will depend on how you ride. For myself I'd start by trying to find a similar length stem with a higher rise angle. But a lot depends on how well the bike fits you. If you're trying to ride a frame size that is actually too small for you then you're trying to compensate by extending the seat post. That'll make the reach to the bars low. For starters how tall are you and what size is the frame?