Sorry to say this but unfortunately you are the perfect example to others why you should never try build CNC machine on the cheap or without asking advise first.
I've seen this approach countless times and nearly always ends up costing twice the price of good components. Worse still, as is nearly case with you can lead to folks throwing in the towel giving up on CNC.

It really doesn't need to be that difficult. People just have to understand and be prepared that building a Good reliable CNC machine can't be done cheaply. Trying to do so just leads to frustration and wasted time & money.

So again GOLDEN RULE. . . . NEVER BUY ANYTHING WITHOUT ASKING ADVISE/OPINIONS.