@OldOrMaybeNotThatOld I also could have written your post myself.
Lacklustre is exactly how I feel about it. Oh and 'rats bag of conflicting thoughts all day long' - yes this is me!!! 
The only people who understand how rage-inducing, shit, uncomfortable, and FUCKING ANNOYING this process is, is those of us who have been/are going through it.
Not helped by it being quite expensive where I live.
I'm a bit the same in that my husband (and family, friends) etc are super supportive/positive/excited about the whole thing, and I'm just.. meh. None of them have been through it. I know they're trying to be nice, but they just don't get it.
Your life is on hold and it just feels shit.
I have had one round and am dreading the rigamarole of the next one.
I really want kids, but when faced with the invasive, expensive, unpleasant and time- and life-consuming reality of IVF... you start to question how badly you want it.
I'd like to renovate our crappy 1970s kitchen, or get a puppy, or go on holiday, but I can't, because every spare cent is going to go in the IVF fund, to pay for a procedure which is likely to fail. It's just so shit.
I'm constantly torn between wanting kids.... and also wanting to reserve my energy, body and bank account to do potentially much more exciting stuff (travel, further study, career, volunteering stuff in my community) in my older years. I'm not kid-crazy but am told I'll love my own, be a great mother blah blah blah.
Husband and I have agreed to do three rounds than reassess. I think having that goal/end point , where the whole thing is up for reassessment, helps me not freak out by thinking too long-term.
Sorry I'm not much help - just hope you know you're not alone in feeling this way! I also wanted to acknowledge that having a partner with their own children must be a further complicated issue in how you're feeling.
Good luck and hope you can feel clearer about it soon:)