Quote: "Iam not any amecher"
Quote: "I will not stop using stock media in these enviroments unless I find something, more, you know, quality"
Contradicted yourself there. If you want to prove you're not an amateur, take some initiave and make your own media.
Also, Darimc hit the nail on the head. Just because you aren't making a horror game doesnt mean that you can neglect lighting. Lighting is a massive part of game design, and currently, your lighting leaves a lot to be desired.
You don't have to make it dark, or add flickering lights, but add some decent lights which cast dramatic shadows. Look at every top title out there which you would describe as "epic", and what you want to aspire to. Now look at how the scenes are lit. Does the lighting in those games look bland to you?
Paul