If only @mahgister was around...he could give you quite a few "tips" on what to do while spending little money. Your room may look like a mad scientist's den when you're done but you'd tick the not cost much box.
I would try using the Sumiko Setup on your speakers. They often end up at different distances from the front wall and non-matching toe-in but it works when you don't have a perfect room. Here's the instructions I use: https://www.audioaficionado.org/showthread.php?p=979168