mrshope I was/am you! My DD is by far the 'hardest' of our NCT group - they have all said it (nicely, when I was saying I wasn't sure a second was viable, as DD is so much hard work!)
Until 14 weeks, when her colic vanished, she was awful. I loved her, but I wasn't in love with her the way you feel you should be. Now, at 7.5 months, she is fun. She pulls up on furniture, crawls, pokes her head round doorways with a cheeky expression, wakes up cooing and calling for me instead of screaming like she's being poked, smiles all the time, sleeps through mostly, and is getting cuddly (she was an anti-Velcro baby).
I totally understand. I didn't enjoy her at first. I endured her. DH helped me survive, as did my awesome MIL who babysat loads, letting me have time to myself.
Re: reflux, do you have a diagnosis? The other 'difficult' baby in our group transformed overnight when they got a diagnosis and infant gaviscon.