Advice for first trimester (first pregnancy)

Hi all! I am in the first trimester of my first pregnancy (10 weeks) so far everything has been developing normally. I’m 32 years old, relatively healthy though have allergy induced asthma and my vitamin D, b-12, and iron levels fluctuate between healthy and very low. I feel very paranoid at times that certain things I do may impact the fetal development but also find certain recommendations to be too hard to follow. For example, as soon as I found out, I cut way down on caffeine and am down to half a cup of coffee. I tried to stop all together a few times and ended up with a horrible headache that I can’t do anything about because I can’t take pain relievers or drink herbal tea. I also have had a lot of food aversions and am struggling to eat eggs, meat, and a lot of veggies. I’m worried about not getting enough protein. Snacking has been ok because it’s mostly been fruit but meals have not been the best (Mac and cheese, grilled cheese, chicken nuggets, oatmeal) essentially what a picky toddler. I want to eat healthy and limit process foods but processed foods are giving me less aversions than the good stuff. And for exercise including Pilates and strength training, I hear so many mixed messages because I know regular, low impact exercise is recommended but then I also hear that certain movements are not good for pelvic floor or whatever else. I want to exercise and be as healthy as I can but I don’t want to do anything that could make things worse for the baby and me. Last of all (at least for now 😂) I thankfully have always been a side sleeper but have found myself waking up on my stomach or back at times AND IT FELT SO COMFY. I also understand those positions are not recommended but what can I do if I can’t control it? I have family and friends I could turn to for advice but my husband and I agreed it would be best to wait until 12 weeks after we’ve had genetic testing. For those who have been pregnant before or are much further along than myself, what did you take seriously? Was there anything you let slide? And if you feel comfortable sharing, I’d also love to know the outcome of your experience either way. Thank you for your responses and for letting me rant.