I'm really sorry to hear of your current feelings about your home theater room.
Your experience resonates with me given I'm currently finishing a home theater room in my house too. Although I completely understand many here enjoy building a "getaway" room, I personally prefer a room that is integrated into the rest of the house. I've been renovating our living room, which is the first room in our house, just off the front door hallway. It has been very tough balancing aesthetics with my desire to ensure controlled light and audio reflections for maximising the performance of the system.
Decor-wise, I'd been going darker and darker, for fear of compromising the image. I'll have a dark brown rug, big dark chocolate brown sofa, and a dark brown (fabric treatment) dropped ceiling - a sort of big square above the seating area, which would also house the pot lights for the room.
At the same time I didn't want the room to feel like a cave. At the last minute I switched the wall fabric to a much lighter shade, because I was fearing the original choice would be too dingy. Very, very glad I did it as it allowed more light contrast in the room. Then the painting started. We had the ceiling perimeter painted a very dark brown, as originally planned, so the dark dropped-down portion of the ceiling would blend in. Once I saw it I felt "yikes!" It really gave a cave-like atmosphere to the room. It really had an "I don't think I'd want to spend time in here" vibe that I think you are getting at. So I immediately had the painters repaint it the same light color as the wall fabric. HUGE difference. Now the room feels taller and airier and more light filled, even though a large central portion of the ceiling is still dark. Now the room does feel like a place I could hang out, day or night.
The way I'm combating reflections of this brighter wall is having matching chocolate brown velvet curtains at the side of the screen that I can pull out along the walls when watching a movie. Also, I made sure to have plenty of lighting in the room so it won't feel dark even at night.
Although all the furniture is not in the room, it seems I've got just the balance going that I need: allowing a good portion of the room to be light colored (walls/part of ceiling not near screen) gives the lightness, contrast and balance to the room, keeping it from being oppressive. Then when movie-watching time comes, curtains will help ensure good performance picture-wise.
If you keep finding your room oppressive, I'd think you can always add changes that lighten it up, but in a smart way that won't (hopefully) compromise performance much, if any.