Do what your gut tells you to do.....a trainer would certainly help you iron out any doubts you might have. Any trainer worth their salt will be able to display some of the capabilities your dog has and in doing so, will help you realize that all is not nearly lost whatsoever. Your attitude regarding " The only thing I can think of is going to a trainer to show me what I'm doing wrong." sounds very open minded and definitely a good mentality. The trainer I hired made me feel rather inadequate as he was able to get immediate results....which I was struggling with..of course. Once he helped me understand the processes involved, while clearly demonstrating his methods ( with results ) it opened my eyes on how to proceed and obtain much better results.
One last thought...getting a trainer ( hopefully a good one ) is a commitment of sorts and shows that you want this to happen and are willing to put the effort in, which is required.
Hang in there and stay the course as you get educated.