I am broken hearted and in so much pain

We are currently raising a 5 month old baby and life has been so stressful one day I nearly walked into oncoming traffic due to dizziness on my route to work. I had good standards for my job and never had a fight with anyone. I thought I had a good job and was just happy taking care of my family even though the pay was small. I requested sick one because I just couldn't do it and my boss requested a doctor's note. I decided to go the cheap route with the note, he called the number, and later fired me, along with stacking infractions to try to get me fired all within a period of just two days prior him calling the number... I'm so confused, angry, desperate... I don't know what to do.