Take a musician friend with you when you are trying out equipment to get another opinion. Utimately, it may be easiest if you decide on a microphone first and then try different amps for best tone and volume. It mostly comes down to who 'you' are. There is absolutely nothing wrong with that. If harmonica is not in your soul, it's just not there and can't be forced in.
Most people quit new activities like golf or piano or karate for the same reason.
Having love for a specific activity is not mandatory and can not be forced. Time will tell if harmonica is a short lived pasttime for you or a lifelong passion. Either way, have fun and enjoy what you do. Different is good. You may also find it more fun to play and practice with a song or CD that is in the same key that you are playing in.