I have been a member of Mumsnet for a while now. It's only since I moved in with my partner a while ago, that I realised there was a step-parenting section, and by god has it been an eye opener for me.
I was beginning to think that I was a horrible person
That I was unreasonable to think the way I do about my step dc, well, the whole situation really, and that I must be doing something wrong.
I myself grew up with step parents on both sides, twice.... and I thought I knew how to handle it. At the grand old age of 41, this is the first time I've had to deal with any kind of step parenting and it's been a proper shock.
So to come on here, and see such like-minded people, and know that how I feel is not just quite common, but also pretty normal is a massive comfort.
So thank you. I really mean that, as arse-licky as it sounds 
This place is a comfort in what can be a very confusing situation.