Nikko was 2 1/2 lbs at 12 weeks when we got him, and he had giardia AND coccidia. We don't have any kids, and he is our very first pet (besides a beta fish my old roommate accidentally killed). I completely understand where you're coming from - at first, I was probably equal parts miserable with worry and overwhelmed with love, which is a terribly tiresome combination. For several weeks, I never actually slept at night - it was more like a series of two-hour naps, and my dreams were even filled with worry.
Finally, after we were sure the parasites were gone, I started to relax a little. Then, after his potty training started to get better, I relaxed even a bit more. And it also really helps that he's reached 5lbs - he can jump on and off the couches himself, he's easier to see and do the "yorkie shuffle" around, and I no longer worry about hypoglycemia on a daily basis. He's also all vaccinated, so we can take him on nice long walks, so he behaves better when he's indoors and so that's less of a worry too. I think the only major worry I have still looming in front of me is the neuter/teeth pulling, lol.
It's all getting better though, and I absolutely thank YT members for being here and helping us through everything, whether it was direct replies to my posts or posts from the past that I searched and read through. Even when there's not direct advice or a clear cut answer, there are at least other people out there who are sharing your concerns and experiences, and that really feels good.
We will have had Nikko for three months at the end of February, and he will be 6 months old, and I am amazed at how much he has changed and how much I have changed - all for the better, in my opinion. I'll always be an obsessive worrier and obsessive researcher, but after you have your pup for a few months it all really does become easier and less stressful. Occasionally now I think to myself, "well maybe it would be nice for him if we got him a playmate..." And then I pinch myself and think back to how difficult the first couple of months were, lol. It was worth it, but no way am I voluntarily putting myself through all that again so soon!!!
Haha, but anyhow - take it from a fellow first-time mom and worrywart, my point is IT DOES GET EASIER!!!
Lauren & Nikko