Oh dear, but at least you can get along without the walking foot. I was going to "re-suggest" using an ironing board for support, as that helps me a lot, but that certainly isn't the problem. I suspect the side that doesn't look so good actually looks better than you think. Walk away from it for a few hours and then come back and look. And, if you wash it, it will probably all look the same. Good luck.
Dina