That my first ever relationship should lead to marriage

Quite a number of posts I've made about the subject, but here goes. I have a girlfriend who traveled out of the country. It's been six weeks, and ties are definitely getting strained. She's coming back next week, but recounting how I've felt about us these past two weeks, I'm super considering ending it. I get this general...like, vibe of disinterest from her, and it, in turn, ends up making me feel disinterested too. It's mostly about those goddamn blue ticks man. Those goddamn blue ticks (not literally of course, haha). It's especially painful when I go to send a text to check up on how she is and find out she's online but not replying. I know there's the whole 'but you have to communicate. Tell her how you feel!' conundrum, but it feels too wimpy and cry-babyish to come to her with this. And that's also another issue. I feel like I try too hard. To impress her. To be another kind of me, but isn't me. I know my sadness is tainting my view of the whole issue a bit, and so I'll take a few more weeks to see how I feel about the whole issue.
This is more a matter of venting over the issue.
I do want this to last. She's my first. And I was so determined to make sure she was my last, but sometimes I feel I just got excited over finding out that a girl can be interested in me enough to actually accept being coupled up with me.
So am I fighting a lost cause?
Should I give up and let her be?