I haven't enjoyed any of my pregnancy and I have found it really depressing at times. As we seem to read all over the place, the second trimester is when you get your energy back and feel good and all that sort of stuff - I seemed to miss that stage too. I am now 37 weeks and still feel nauseas every single day, there hasn't been a single day since about week 6 that I have felt like my usual self. I also found it really upsetting that I had turn down every social activity that I would usually take part in and I really miss 'me' (sounds silly I know). I was thinking that I would have 9 months to just enjoy my life and my husbands company and make the most of the time before the baby came - not likely.
I'm sorry you are feeling upset and I know exactly where you are coming from.
Hope it gets better for you.