So I dont understand the way my mind functions. Options

[IamRad]

I know this post is really long, but i really need an answer.

I guess i'll just start from the very beginning so the story makes sense?

So about two months ago, I started talking to this guy alot more, and eventually it came to the point where i was starting to like him, and i started noticing that he may like me also...So on New Years i just decided to start a new year and tell him how i felt. Turns out that he did feel the same way. From that day carrying on for like two weeks, i couldnt eat sleep, or concentrate, just because i was super happy. I mean, ive never had someone really like me before, so it was a new and exciting thing. everything was going amazing, we stayed up all night on the phone getting to know eachother really really well. Then about a month later he decided to ask me to be his girlriend, and of course i said yes. Well we are currently together...

Now here comes the part that i dont understand.

Almost every weekend, i get these weird thoughts in my head. Like thoughts on how this relationship may not work, and what might happen if we break up, and things like that. I mean i also think of things that might stop me from liking him... (Now i say this happens on weekends mostly because i never see him on the weekend, i think?)
So i talked to my good friend about how ive been having these thoughts, she said it might be because im a girl and girls always overthink things, which i guess is true...but the thing is WHY do i think all of this, it doesnt seem normal to me...
The reason im posting this is because, this whole week ive been thinking about what i usually think about on the weekends...weird right? i thought it was only a weekend thing. I feel like im pushing the best thing in my life away..

The question i have for someone who is actually willing to read this:

Can someone try to explain to me why i feel this way? Like have you ever related to this kind of "problem?" Why do i make things so complicated when things are so perfect and simple?

It makes me so upset that i actually think these things, because it makes me feel so dishonest with him...but im not sure if its something i need to talk to him about, since its my mind playing tricks on me? i dont know..

[IamRad]

what everyone replied makes alot of sense, so thank you :)

and the person who posted above me, i think i'll just keep doing that over and over again until eventually it goes away by itself... i hope :)