You can get an adjustable stem like this one (I have two and like them a lot).


If that doesn't give you enough height, you can also add a stem riser like this.


I have longer bar ends on my comfort bike (like these) that I have wrapped so they're quite comfortable. I have mine horizontal and used to sometimes lie on them. And it sounds crazy, but I found that clip-on aerobars were very comfortable (as my elbows could handle the weight quite well where as my wrists just didn't like it).

I did also have thick gel gloves that helped (but make sure you remember to change your hand position frequently). I personally found that being almost upright, my issues largely went away. I just didn't really like being that upright when riding (I now ride a 'bent).

Cheers,
Charles