When am I allowed to start feeling discouraged?

Lindsay • Married to a wonderful man! We got married April 4, 2015. We are now TTC #1 and we are super excited and very hopeful!
I've been ttc for 2 years....I've been on clomid for 9 months and nothing has happened. I took a month off because I had surgery to get a better look at what's going on in the reproductive organs. My dr said he cleared up some endometriosis and is very confident that's what was setting us back. I feel like I did the surgery for nothing. I'm just feeling down in the dumps. I really try not to let it get to me, but it's hard. All of my friends have kids and all I've ever wanted it to have a family of my own. I'm sick of waiting! I really do have wonderful, supportive people around me. Sometimes their positivity is too much. Sometimes I just want my hubby to show how he feels. He's told me that he feels like he constantly needs to be strong for me.