I don't usually use natal placements to support horary reading but the ASC of the horary describes you. Also, you currently have Saturn RX transitting your 12th house. Psychological restlessness is expected.
Venus is the natural significator of many things, but its most famous functions is love and marriage or serious long-term commitments. Are you currently married or in a serious relastionship? If you are, is there trouble in the relationship? Venus also signifies material security. Maybe there's something that you have to achieve in one of those areas in order to get a second child.
If you don't mind me asking, why is it such an inner wound not give your child a sibling? Having childen says nothing about your capablities as a parent. And it's not exactly something you "can" or "cannot" do. There are many other factors involved and you shouldn't evaluate the life you're offering your daughter based on this. Besides, many children have no brothers or sisters and are leading perfectly happy lives. Don't worry about it.
One last tip. I have heard many times before, from doctors and women, that worrying about achieving pregnancy can be the very reason why it cannot be achieved. You need to be totally relaxed. Also, too much worrying may negatively affect your relationship or marriage. Maybe that's what Venus is signifying. I could say more, but what I have to say shouldn't be on a public forum
. Just focus on the love instead of the pregnancy and everything should turn out ok.