Worries..

This might be long but I just need to vent.. 
I graduated high school 5 years ago this upcoming May, I haven't been in very lengthy relationships since until I started dating my fiancé. We've been together a year & a half, but I've known him since high school as we use to work together our junior year. We got engaged about 2 months ago & the wedding is in 8 months {it'll be an elopement/destination style wedding}. I've been very fortunate that the photographer I chose doesn't charge for elopements, so I don't have to pay her, just her plane ticket & hotel room. Same with my videographer. I'm brining 4 people with me & he's bringing three. A few nights ago we had dinner with his mom & mine to chat wedding details, my grandparents {who do very well for themselves} offered to pay for the dinner that we'll have the night of the wedding and my fiancé wants to pay for his mothers plane ticket out there.. The entire time we're talking pricing & what not, she never offered once to pay for anything or pitch in. And I know it's mainly the brides family who covers everything but it would've been nice if she had offered to pay for something. 😕 So back to the "not being in a lengthy relationship since high school" problem.. This is my first one since school, but this isn't my first lengthy relationship ever. But for some reason I am terrified. I'm scared of getting married, I can't stop overthinking things.. My mom has always said to my sister & I that if she would've dated my dad for 6 more months she wouldn't have married him. What if that's what I need? Like do I need more time? Am I just freaking out over nothing? My family is very exposed to things, like I said my grandparents do well for themselves & they enjoy traveling, so we go and see a lot of new things across the U.S. His family didn't do those things so anything he sees that's different is such a culture shock to him. Which there's nothing wrong with that, it's just different to me.. There's so many red flags that pop up, but not necessarily bad things, just things that I don't know if I can deal with. 😔