Chilbi, yes yes yes. I've very much felt like that. The age you're at is such a hard time, it really is. Don't beat yourself up too much, yes it's bloody annoying when you seem to be the only one with a sleepless child but it isn't the case, there are thousands that don't admit to it. You should try and focus on something else when you're with your friends. COuld you politely tell them that you're feeling a bit down about lack of sleep and you want to steer clear of the subject? I know Tam has said this, and I agree, mn is a fantastic support but it's also a bit of a curse. I found when I was at my lowest mn was my saviour but it also made me obsessive about sleep. I spent far far too much time worrying about it. Of course this is another one of those occasions in motherhood where hindsight is a wonderful thing but you have my word. It does get better.
From memory, 4/5 months were the worst, little unsettled at 6 (due to weaning I think) settled down much better and consistent at 7 months, slight regression at 9 months. Been much better since about 11/12 months. It has definately got better, easier and more predictable through doing nothing. We tried PU/PD at 4 months which was awful we tried gradual retreat for a while which was good but I gave up when she learned to pull herself up as it was like a jack in the box so we reverted to cuddling her to sleep. These days we lay with her and then transfer her to her cot when she's down.
My advice to you would be this. Ignore all advice, discussion, reading, writing about sleep for one whole week. On those mornings you feel terrible, instead of wallowing and searching for answers as to why your LO doesn't sleep, get out. even if it's just to the park for a walk or to sit in the library. Sometimes being out just makes these things seem less important. During this week remember the SIFTW mantra and repeat daily, "it is just a phase". I pretty much guarantee that after a week, you might not be getting any more sleep, but you will feel a whole lot better about it.