By 8 months your LO should be able to do 3-4 hours wake time. You need to transition to a 4 hour EASY routine. how many bf a day/night? and yes she should be having 3 meals a day by now, not large meals, her main nutrition still comes from the BF, but try doing a morning and lunch solids meal about half and hour to an hour after bf. What food has she had so far?
If she is having 2 naps that are more then 2 hours then she is having to much daytime sleep which is effecting her night sleep. Yes good day sleep leads to good night sleep, but in moderation, right now there is a little bit of a night/day confusion I think.
When you transition do it 15-20 minutes at a time until you reach 4 hours. Don't rush her, follow her lead. She should be having 2 naps of 1.5 hours at this age, start waking her at the 1.5 hour mark, your EASY will start to be AEASY and thats OK, as she gets older you'll notice that EASY will continue to change. You've done a great job of listening to your LO
just continue to listen and make the changes so that they are easy on you both.
Try to aim for a bedtime between 7-8pm, if you don't have a bedtime routine start implementing one now, the earlier you start the better. As for the nursing to sleep at night, I'm not to good with that as I don't have that problem, I recommend you ask at the breastfeeding forum and they may have some good advice for you.
Sounds like your doing PU/PD right from what you said, but I have a few questions, are you picking up with a real cry or a mantra cry? you may be doing it to early, you may not, its a hard one. PU/PD is a lot of hard work. The first night I did it it took me well over an hour, but everyday it did get better. When she cries do you stop putting her down? or do you put her down anyway? have you tried just laying your hand on her and not picking her up right away when she cries? Also can your LO roll over or pull herself up in the crib? does she do so? if she does have you tried just PD at all? and finally does she have a lovie at all? if not try introducing one.
I completely understand your dilemma, especially as a mother who has a child who doesn't like to nap
when she goes to sleep I really hate to wake her, but you need to balance it so your LO is getting the right amount of day and night sleep. She should be going 10-12 hours at night, not necessarily strait through, she may need a feed since she isn't used to sleeping that long, but she may not, but try to restrict day sleep to no more then 3-3.5 hours and you'll likely see an improvement, be ready to have a much earlier bedtime when you switch the naps as she will be tired. The first week will be the hardest, but as she gets used to it, things will get better.
Don't fret, your doing a great job
and will these new things in place, you should have your evenings with your DH back again, and they are well worth the effort.
HTH