Depression when TTC

Hi I know I'm not the only one but I'm feeling really down. Me and my SO have been trying for a baby since December 2014 and I'm still not pregnant but the thing is I was on the depo injection but I only had one shot which is suppose to last 12 weeks and my body is still messed up, Ive had a irregular period since March 2015 and  it only lasts 2 days. I'm getting really depressed and I'm having some really horrible thoughts that maybe I'll never have another baby or I'll be trying for ten years before it happens again. I'm starting to lose hope