Getting down about my chances....

My husband and I have a beautiful 8 year old daughter and we've been ttc since she was 2 off and on. We've been trying harder than ever the past 2 years and we've only been successful once, only to have it end in miscarriage at only 4 weeks, I didn't have a DNC or anything. I've had tests to check my ovaries and everything is fine. My hubby is healthier than ever as he's lost 85# since last July, I've lost 30# since then but I'm still 40# more than when I got pregnant with my 8 year old. I just wish it would happen and other than taking vitamins and using ovulation tests idk what else I can do. It seems like everyone else around me is getting pregnant...