My daughter did injections at our family Dermo Dr early on, when spots were small and also used Rogain for men.  Her hair did grow back for a short time but then fell out again. The family Derm Dr did provide a topical numbing gel that stopped all pain during the injection, however my daughter would stress out about going to get the shots. 

Please read my post on DPCP.  Everyone is different - but honestly I have done it ALL.  DPCP along with Vit D, Allegra 180mg and Biotin Forte with zinc and stress reduction has led to our daughter successfully growing her hair back and keeping it now for 2 years.  Best advise:  Find the Best of the Best Dermatologist that SPECIALIZES is Hair loss and AA (including the use of DPCP).  Ask their success record.  I know your pain.  I cried every day for months.  It may be hard to believe now.... but it does get easier.