You aren't doing anything wrong if you feed her frequently. It could be a growth spurt which will end soon, or it could just be her being newborn and wanting to be cuddled and nourished and comforted lots. She definitely will grow out of her grumpiness and become much more communicative very soon. In the next few weeks (if she hasn't already) she will start smiling at you, and then saying 'Agoo' whilst gazing adoringly at your face. And not long after that she will start reaching out for your face and wanting to 'gently pat' it - in DD's case this usually meant pulling very very hard on my nose but the thought was there. It will all feel fabulous once it happens.
But in the meantime...
My DD wanted to feed every hour between 6 and 8 weeks and cluster feed every evening. It stopped literally overnight around 8 weeks, and although she was still awake in the evenings until around 16 weeks she was a lot more chilled out and happy to spend time just sitting on my knee and looking around.
But 6-8 weeks felt like very hard work for me and I did spend a lot of time thinking I must be doing something wrong. Things that might help:
Going with the flow as suggested above. If possibly don't count or time feeds. I found that really hard to do, but once I finally was able to let go of the idea that DD 'ought' to be able to go three hours between feeds it all became much easier.
Get out for a walk at least once a day, either with your DD or by yourself if you can leave her with someone. Or get someone else to take her out for an hour in a sling or pram and grab some time to yourself.
Pop her in a sling between feeds if she is happy to nap in one, then you'll have two hands free to get on with things (one hand for tea and one for cake).
Even if you can't sleep during her daytime naps put your feet up and chill out. Don't hurtle around cleaning the house and putting away laundry like I did. I haven't ironed anything for nearly 8 months now and nothing bad has happened.
If you have family and friends making unhelpful comments about how she 'can't possibly be hungry again' rehearse some comebacks (even if you don't actually use them). My MIL was fond of telling me DD only 'needs' to be fed every four hours for ten minutes or so. So during one of her visits I counted how many cups of tea she made in one day and pointed out that the longest she went between drinks was 1.5 hrs and maybe my DD just took after her. MIL is lovely and she did shut up after that.
Eat little and often yourself and try to eat fairly sensible smallish meals. Make sure you have a good variety of food in the house to tempt you. I was ravenous and can remember getting bored with eating chocolate hobnobs which I would never have imagined could happen. My Mum who bf twins said that when she stopped after a year she fasted for 48 hours because it felt so good not to eat for a bit!
At some point your DD will calm down again and start sleeping for longer periods. Then she'll have another growth spurt, then she'll start teething, or you'll introduce solids, or she'll learn to crawl and everything will seem chaotic again for a while. But I've found every period of chaos after the 6-8 week one much easier to handle because I know it will stop soon.