Depressed...8months and still nothing :(

So my husband and I got married May 31, 2013, and ever since then we have been TTC. My period has been so off! There was a month where there was 32 days between my periods, another one was 28, and there was even one that was 40 days!! It gets so disappointing when I find the tests to be negative and then AF comes a few days later. I even have some of the symptoms as well (tender breasts, throwing up, sensitivity to smell...ect). Both of my sister-in-laws are pregnant (one is about to have her 2nd child in February and the other is having her 3rd in September), and it's depressing to me that I can't even get pregnant once, and I married the baby of the family! I was told that prenatal vitimins can help with making you fertil,  nd I've been taking those. His mother told me that we're having problems because he has a hydrocel (he was hit in his sack with a baseball bar when he was younger, and the sack split on the inside and now has fluid around it), but I looked it up and that shouldn't cause infertility. We don't have health insurance right now and I didn't know what else I could do to help us conceive. Any suggestions??? I feel like time is running out because I'm going to be 29 in March and I have no children yet. I just want to stop having to cry whenever my test says BFN. My husband even feels bad bc that's the only thing I really want, is to be a mother, and it's always the same it's never going to happen. Any suggestions????????Because this is super depressing! Thanks in advance for any advice!