Am I the only one?

Sa
I seem to go back & forth quite a bit over whether or not I want to have kids. About 4 years ago my husband (boyfriend at the time) were trying and really wanted to have a baby, but quickly learned it was going to be a struggle for us. I'm a bit overweight and spent the following 2 years seeing multiple doctors and figuring out different diagnoses. Long story short, we have never conceived. 
I'm also an Environmentalist and there's a huge part of me that is terrified to bring children into this world considering the state it's currently in. When I think about what the planet will be like in 50 years, I'm truly terrified, if things don't start changing for the better (& right now they're only getting worse). 
If I'm being honest, there's also a selfish part of me not wanting kids. I've always been a self-proclaimed "wanderer" & love traveling and doing things on a whim. 
Along with this "selfish" reasoning is a desire to have kids so when my husband and I are older, we won't be alone - we'll have family surrounding us.. kids & grandkids. I grew up with a sister and over 20 very close cousins and absolutely loved it. My sister just had a baby and wants another. Part of me wants to have kids so they can grow up together as close cousins. 
Then there's the part of me that worries I'll be a horrible mother. There's also the fact that my husband and I are business owners (of a martial arts & yoga studio) and we barely make enough money to get by - so how are we supposed to have kids?!
I'll be 32 next month and am hoping to spend a few months traveling abroad to obtain yoga certifications and I feel like my biological clock is almost up. I've always envisioned either 4 kids or 0 kids - which may seem crazy considering my concerns - but I feel like I'm getting too old. 
Wow - this is long. If you've read this far - thank you!! I'm just so conflicted & wonder if there is anyone else out there who may feel the same way? 
I don't mean for this post to worry or offend those who want nothing more than to be parents. 
Thank you!!