OK - first, breathe in through your nose and out through mouth.. come on now.... deep breath in....... and let it out.... ok....
We are paying for the wedding ourselves.

As a matter of fact I took out extra student loans so we could pay for it. With that said, we made up our guest list... we both have enormous families, so we cut it down to immediate family and only those first cousins we spend time with. That right there brought our invite list to 115 - much higher than we had anticipated.

We did not feel obligated to invite anyone. Since it's a destination wedding, many people don't feel offended... we said we'd probably have a BBQ in the spring for all those who couldn't join us. There were about 8 people between my mother and my FMIL they wanted us to invite. Our stipulation was, you are more than welcome to invite them as long as you are paying for them. Especially the folks on my mom's side - I don't like them, they never come to any family function even after they RSVP yes, and I don't feel like I want them to be a part of one of the most important days of my life... so my mom said she'd pay for them if they said yes.

Whatever.
Invite the people who are most important to you - the ones you couldn't imagine not spending your day with. And then you can always do what so many of us are planning on doing - have a get together when you get home. Don't stress about it and don't let anyone bully you into anything. It's your day, not theirs. They've already had theirs.
Just remember to breathe..........