What Causes Stress,tiredness, Dizziness And Light Cramps?

I had unprotected sex on the 9th of September I started my period on the 11th of sep abut I've been stressed and my anxiety is so bad plus on top of that i've had a mono flare up that im still not over its been 4in weeks. Well now I feel tired and dizzy and sick to stomach with light cramps. I know im not pregnant cause I've taken 2 test and they both came back negative
what is wrong with me? I looked up stress symptoms and anxiety anf I have s
most of the symptoms