I used the June Tailor spray once, as it was a donation to the school. (The kids were making a quilt.) I don't care for it. That said, it worked fairly well. It did gunk the needle some and was really hard to clean up. Maybe you used too much.
I would switch to the larger needle, which has been suggested. I would also switch to 100% polyester thread. Double check your threading to make sure it's correct.
I feel your pain, but can't think of anything else that might help.
bkay