I hated it too! I love being in water, had watched the videos and was sure that I would enjoy a water birth. However, from the moment I got in, for my first birth, I realised it was not for me.
It was too hot for me
It was not the right size - I have floated, half sank/couldn't get a comfy position going
It didn't have any pain relieving qualities for me, infact it speeded my labour up dramatically
I hated wasting the water - it had taken ages to fill just for me, and they have to drain it afterwards, so I stuck it for an hour. However, I quickly realised that I much preferred being curled up on a bed. With ds2, I gave birth on a bed, with a bean bag and several pillows on the bed - basically I had build a nest!
I think it is helpful to ask yourself what you do when you feel unwell? Go for a walk, have a bath, or head to bed? (I love being in water most of the time, but if I am poorly I am an under-the-duvet type of gal!) Whatever your answer may give you a clue as to what you will want to do when birthing