Indoor Close Quarters

I take most of my shots outdoors, but mostly because my gear prevents me from capturing subjects in the close quarters of my home. My rooms are fairly small, would it be worth it to consider getting one of those wide angle attachments? They typically fit just my 18-55, but that lens lacks the sharpness that I prefer for most shots. All the wide angle alternatives that I would consider are going to be 350 and up, and I would rather be investing in longer range lens at this point. Thoughts?

The wide angle "attachments" are a waste of your money. If you dont like the sharpness of the 18-55 its only going to be worse with one of those things added.

18-55 isn't a great lens IMO if you're going to invest in a lens that will work in close quarters, go with the 24-70 or the 35mm
Canon does sell a non L 35 mm which is ok

Indoor close quarters images from a Canon 18-55 image stabilizer lens.

Please analyze and identify any flaws in these images.

I have a 35mm 1.4, but its manual. In close quarters it is almost impossible to keep up with a moving subject in my space. Also keep in mind im on a crop so im losing some of my subject, should I simply solve by inverting my camera?