I would like to see a vid of your deadlift to visualize your form.
Putting on a suit at a competition that was not used prior, is ill advised. More of a sport specific thing and practice how you play. Wear it to train and even get a tighter one for competition I you like.
Many of us get stronger in the deadlift when we don't actually do it. For instance - I added 45lbs to my dead (760 to 805) when I learned of pull-throughs and stuck with consistent box squatting with bands and chains to really overload my weak points. Correct box squatting destroys my lower back (in a good way) and I stick to the dynamic/max training methodology (Westside/Elitefts)
The key is to find your weak points, fix them, and train for a solid core with perfect technique. Best of luck....