chin up bulldog
your 1st comp experiences and emotions mirror my own exactly!
i had played well leading up to my 1st comp but like you the weather was less than helpful and i had a completely sh*te round!
2 comps later i had my PB 14 shots less!
a round of golf is a round of golf the only difference between comps and social golf is about 20 yards!
i think its a bit early to state that you are sh*t at competitive golf

lower your expectations mate,relax and enjoy your golf!