It might be possible because when we are stressed we don't eat properly also stress hormones can weaken immune system. You must see a doctor to address your concern, it's not possible to diagnose you from an internet website.
You don't have an HIV concern, you were never at risk.
Not a risk for HIV transmission. Tattoo needles can't transmit the virus. No one has been ever documented to acquire HIV in this manner.
Your symptoms don't relate to HIV, please see a doctor for them. You don't need to test.