I can stand on a MTB just fine. But if your hybrid has the bars closer to the seat than it'd be on a road bike, that will make standing more difficult. You can try putting bar ends on the bar to make it a more road bike like position for standing.

As far as getting used to a higher gear, just try riding the climbs in a higher gear. Use the granny but shift up one cog from what you'd normally use for that climb. If youre one of those riders that automatically dumps the cassette and chainring to the lowest gear for every climb, stop doing that. Shift down as you need to, not before.

And for getting used to standing, shifting up a couple cogs is good advice as most people can't pedal as fast when standing as when sitting. Being able to stand is a very useful skill, even if you have low enough gearing to let you sit. If nothing else it lets you stretch on long climbs and use slightly different muscles.

Edit: I see that you have bar ends. Try setting them so they are nearly flat, just angled up a bit (10 degrees or so). That way they are at a natural position when you stand.