I'm 25 years old and for the past 12 years or so I have been riding a ~15 year old Apollo mountain bike. Today I bought myself a new Trek DS 8.5 to replace my Apollo, which is on its last legs. I mainly use my bike to commute to/from work during the week but I also like to ride trails whenever I get the chance, which is why I chose a hybrid bike.
I literally bought it in store this morning so I have only had the Trek for a few hours, but already I'm a bit concerned about it. Riding this bike feels 'stiff' - even on an even road surface I'm finding I need to put more energy into my ride to achieve the same pace I could by barely pedalling on my old bike. And keep in mind my old bike was no cruiser - it was getting old and stiff itself, which was the entire reason I decided to replace it. I'm also having a hard time finding a middle ground with the new gears; they either seem to offer too much resistance or not enough.
My question is whether this is considered normal for a new bike or is this simple the nature of a hybrid? I haven't ridden a brand new bike since I was a teenager so I'm wondering whether I've just forgotten what a new bike feels like, but I really don't recall ever experiencing a bike that feels like this. Are there any adjustments I could/should make or should I consider going back to a mountain bike?