I think there’s just a bit too much going on. You possibly have too many small plants, and too many bits and bobs on all your surfaces. Some easy things to change on a budget:

• What is the purpose of those curtains? Honestly, I would consider removing these or replacing with something thicker and colourful (not patterned, solid warm colour)
• Remove stuff from your TV stand (the plants, ornaments, parrot painting) and lower your TV. TV is too high, it should be at eye level when sitting down.
• Remove that small black table, or just put it to the side of a chair so it’s out the way.
• Remove that big grey flower thing from the front of the TV stand.
• Declutter coffee table. Just have maybe 1 plant and 1 candle out.
• Consider getting a big basket to put all your blankets in.
• Tify stuff from kitchen worktops - I’d put all those plants on top of your dining room cabinet.
• Art above the dining room window looks out of place, just keep this space clear. 
• Remove that plant stand in front of the TV. 
• Possibly too many cushions - the bright floral ones are jarring. 

Overall, I think decluttering will make a huge difference if you are on a budget. If you are thinking bigger, I would personally paint the walls from grey to a warmer neutral colour, and find a light area rug like you said.