You may find the Sweet Potato, might also be an issue. You might be wise if needs be, to switch to something like Broccoli, as it's high Carb, low GI, so the fact you'd be eating low GI, might help, plus large stalks are 10g Carbs, so easier to portion out.
The main thing is not to panic. As discussed before, it's easy to get like that the first time, as you've nothing to work with / compare to, that seems logical, if needs be, you could consider increasing Cardio, or possibly have a shock day at some point, where you eat around 2,000 calories, for one day, then get back on the system again.
The main thing for now is give it time. You've got more than 2 months to get the way you need to be. Even if it came to the crunch, and you were 1-2% over the desired fat level, you could still cinch some good points, for things like small cosmetic changes to face and hair, smooth tan, good presentation, posing, routine and muscle size.
There's others who could have a weak routine, or some poses that fall through, or be over studded on the suit, etc etc, so it won't mean you get a poor finish.
At this point, it could quite easily be the case that you nail the fat% anyway, even if you chose to do a water load, about 36 hours pre-contest or something like that, so you've got options, so you shouldn't worry too much right now.
You're doing great, and the changes are coming slowly and gradually, not too quickly, so it's about being patient, and sticking to the programme you're on, and if needs be, like you have done, make minor, subtle changes.
I am sure this will work out for you, and as I said, it's normal to question things, especially the first time, but as long as it doesn't make you do erratic things every week or two, that's the main thing.
I know you're going to be fine on the day. You DESERVE this chance, and the only person you're going to let down, if you do crazy stuff now, and get a poorer finish is yourself.
To me you're already a winner, for coming so far physically and educationally, since your teenage years and you DO have the potential to be a great, great athlete, as long as you stick to your guns, be strong, and don't let that solid, positive mindset be spoiled.
That might have been you in the past, but if it was, it certainly isn't now.
GOOD LUCK and keep on pushing yeah

. There's plenty of people including me, who are proud of you and I know 100%, you WON'T let yourself down, or walk on stage looking second best for a second.