I, too would start very slowly and most importantly let Krystal that there is an end. First make sure she is comfortable wearing the harness by putting it on, let her wear it for a few and then take it off. Do this several times a day. Only when she is completely comfortable wearing the harness and with you putting it on and taking it off attach the leash, leave it on for just a few minutes then take it off - do this several times a day until she is very comfortable with the harness and leash. Then encourage her to take a few steps with the leash attached to the harness -
she has probably already done this but this time praise her big time. From there YOU hold the leash and call her to you - praise and treat - teaching two things - come - and the harness/leash is a good thing.
The problem with most training is that we try to start at the GOAL. What we need to be doing is to start at a point where you can ask something of your dog and he does it -- even if it just calling his name and he looks at you. Work from there in baby steps making a game out of training. You want your dog to THINK and figure things out with your prompting rather than force him into submission.
Good Luck - have fun with your training!!!!!