A closer matching thread will make all the difference in the world!

Make some practice 'sandwiches' - back/batting/top. Keep the grainline straight between your hands - if you pull on a crossgrain, you'll get puckers and stretch it out of shape. PPP - practice, practice, practice. If funds are a factor, you can use water soluble thread in the bobbin, and when you are done, get the 'sandwich' wet, pull the thread off the top and you're ready to go again when it dries.

Hang in there, and don't forget to BREATHE!!!

When I started FMQ I had to mark my fabric with a pattern and learn to follow it. I am far from perfect now but it did make it easier when I had something to follow.

yes! I have seen meander templates, that's a great idea!

I feel your pain - so many times it just doesn't look right, so I get out the ole ripper. All the suggestions have been spot on - My suggestion is stitch in the ditch - your beautiful quilt has a diagonal "personality" so I would do diagonal stitch in the ditch on this one.
Just my two cents worth.

I have not had much luck with machine quilting. I made myself a couple of sandwiches to practice on tho and with lots of practice, I AM getting better, but only with meandering. I have yet to even try free hand designs. I think the key is practice, practice, practice and do so on scrap fabrics. Your quilt is otherwise very nice and will look beautiful once you get the hang of the machine quilting. You'll feel so good you persevered. Hang in there, it is not easy. Oh yeah, a glass of wine might help. LOL

You can remove the stitcjong with razor blade by JUST touching the stitches, but it is easier to do with small
(28mm or 18mm) rotary cutter. Hold like a spoon and gently touch the threads while pulling the layers apart gentlt!!
Try it with some scrap pieces firdst, A caveat tho: you will have to pick out threads from both sides of your piece as it only cuts not pulls it out as you rip. Good luck and let me know if you perfect the technique.
I have done all my unsewing this way for years and it goes so fast that I do not mind picking off the threads.
It really is a lovely quilt and well worth the time to do over.

I run one of the lint rollers over each piece when I'm done unsewing instead of picking out pieces of thread - works great!

I have been using painters tape that I have in the house from the last time we painted. I actually use painters tape for lots of taping thing. Like for presents. no one ever says anything about my tape jobs. hehe
but the painters tape works great. you wrap it around your hand and pat both sides. picks it up real fast and doesn't make it sticky.

stitch in the ditch around the squares. This will stabilize it for when you do the quilting. the more square quilting design looks better than the other more circular designs. pin and pin as you quilt. Even tho I may have basted the quilt, I still use the long yellow pins in front of the pressure foot to help hole the layers in place.
You might also consider varigated thread. This will give texture rather than new design and will less noticable. It has already been suggested, but it appears that you need more practice to get curves more even and the long lines straighter and more even. ......and go slow. Don't try to be fast. There is more control. And any time you feel you are loosing control of the quilting - such as needing to move hands, stop with needle down and regrip and then begin. Always leave needle down. That way the quilt doesn't shift as you are repositioning. Then when you start up again, let the needle got up and down a couple times in place until you feel you have control and ready to move out.

Thanks to everyone for the great ideas! I am getting ready to do a lot of frogging here pretty soon and intend to now use the skinning method. The tape idea for pulling loose threads is pure genius. HUGS to all.