I feel like I'm slowly falling more in love with my boyfriend the longer we're together

We have been working on ourselves in therapy, and on our relationship by having weekly check ins and calling every day to help bridge the distance gap

We lived together for a bit, but it didn't work out and we broke up, but we've been back together for about a month now and things are going even better than they were before

We talk about our future a lot, and we don't shy away from hard conversations

I've had two big crushes before, and maybe I even loved one of them, but neither of them have been like this one

The difference is I'm an adult now for one, and for two, I'm dating someone who is more similar to me in background and personality/queerness

I'm just scared that since he's my first love he's not going to be my last

I'm scared that we're not going to work out one day and I wouldn't take any of the time back, never

But what if we don't work out?

How do you know when you're in love?