I relate a bit, though my DS is 2 1/2 now.
I was bold enough to nurse my DD til 2 1/2, and weaned because I couldn't handle the nipple pain and strong hormonal icky feeling I got every time she nursed (commonly called the heebie jeebies), but weaning her was non-traumatic. She just fell asleep in my mother's arms in the rocker 3 nights in a row, and I was dry because nursing to sleep was the only time she nursed by then.
Now, I have friends who nursed til their child was 4 or 5, and fully intended to do Child-led weaning with my DS, who is now 2 1/2. But surprise surprise, I am getting strong heebies while nursing now, and my supply dips to almost nothing mid-cycle. Eating ground flaxseed really helped with the severe nipple pain I was also getting mid-cycle, but the heebies are still there, and now appear to be not just mid-cycle.
DS is very attached to nursing, and on top of it, I would continue nursing if I could, because he has food allergies, and can't have cow or goat milk, is also allergic to soy and almond (I make my own almond milk, and it was great, til he became allergic to it!), so weaning has a big price attached. Once he's weaned, I will be jumping through hoops to supplement him daily with calcium, AND lactose which breaks down into galactose which is vital to normal mammalian brain development, AND probiotics, AND DHA/ARA/Omega-3s.
On the other hand, once he's weaned, I can have chocolate, dairy, egg, soy, almonds, tomatoes, blueberries, and strawberries again. Those are his food allergies.
I admire women who do Child-Led Weaning, and expected to do it myself, this time, but it's not working out that way for me. Whether it's because I am almost 37 and possibly in perimenopause, hypothyroid (treated with daily meds, but still), have high testosterone and PCOS, who knows. But for whatever reason, my supply is petering out, and I am getting strong aversions to nursing, nipple pain on and off, etc.
If you can nurse, and want to, I would say go for it, and just focus on finding friends who do child-led weaning or have at least nursed past 2, for support and encouragement. La Leche League is great. Your child will benefit, and of course the benefits for your health are good too.
If, like me, you find you have physical issues that are pointing you toward weaning, then don't crucify yourself. I have learned to appreciate CLW, but also to forgive myself for being human and not having a hormonal situation that is ideal. I wouldn't have considered weaning my son before age 2, but I think I will plan on weaning him before age 3, and I think I can do it in such a way that no one will be traumatized.
For the nutritional deficiencies, my advice would be to resolve them before TTC. Being deficient at conception and 1st tri can have detrimental effects on the baby, and on the pregnancy, and you.
And if correcting the nutritional deficiencies, saves your nursing relationship, even better!
Might I suggest kelp and other sea vegetables as a mineral-rich superfood? If you don't like eating them, you can get them in capsules.
Big hugs and I hope you find the support you need, both nutritionally and socially, to keep nursing, if you really do want to but are hindered by lukewarm social support, and lack of adequate nutrition. Your baby is less than 2, and whereas I won't say she'd be doomed if you weaned, she'll be better off if you can make it a while longer.
When you wean, ideally it will be when and how it feels right in your heart to do so, and not for someone else's reasons, or because of a health situation that can be resolved, and needs resolving anyway.
HUGS!