Protein deficiency is generally thought to be quite rare for people that get enough calories. If you are at a healthy weight and not losing weight, it's likely that you
don't have a protein deficiency. However, it probably won't hurt to increase your protein a little just incase, but you should be considering other possible causes.
Low calcium is more of a concern for vegans than low protein - vegans are more likely to be below reccomended limits for calcium. Also, issues with hair and nails are often said to be possible symptoms of a calcium deficiency and I just googled this and found several articles saying so, (but I couldn't trace this advice back to a reputable scientific study or expert or health organization in the time I had to search for you). I reccomend you google calcium deficiency symptoms for yourself and see whether it seems to match what you are feeling.
Vegans should take specific care to eat specific sources of calcium, such as green vegetables and so on. However, the amounts can often be low. Eating almonds or taking a calcium supplement, or eating tofu with a high level of calcium, are probably good ideas. I suggest you consider a calcium supplement in the short term and see if it makes any improvement.
However, it's fairly unlikely that I can diagnose your condition just from reading a post on a forum. The chances are that it's something else so if you do increase your calcium levels you will still need to try other solutions at the same time probably.
You really need to see a professional ideally, however I appreciate your situation is difficult. You could also try this:
https://veganoutreach.org/vegan-mentorship-program/ You may benefit from a mentor, although I'm not sure whether or not they would give nutrition advice.