Be sure the area where the thread goes in the tension wheels is clear. Many neglect to keep that lint free.
Use an old handkerchief, fold it and pull that edge between the wheels all around. I also find if I put the spool of thread on the holder with the thread coming off the back of the spool, the nick on the spool down and a nice sharp needle helps with the frustration. Decorative threads are for slow sewing, perhaps you were speeding?
Carol J.