Single or not to be?

I am sitting alone at work, feeling bored, staring blankly at walls and on my laptop. Hmmm waiting for the right time to really be alone and start watching my drama. Checking grammar mistakes on my posts but feeling lazy to edit them. Forget about it. Too much things stored in my mind making my head empty.

What should I do?

I'm just a very simple and down-to-earth guy. But somehow I feel insecure, felt like whoever that I like will end up cheating on me.Is it because of my past experience or is it just me going crazy? Can't help myself from overthinking something that's so straightforward and basically there's no other reason behind it but it's just my imagination and assumption. Sometimes I even overthink what not to overthink., Anyone got a solution for this? Am I feeling insecure towards myself or the other person?    

Sigh... Life is tough as it is and here I am thinking of nonsense and trying to be a "detective" checking on everything (some of you might know what I meant). Crazy thoughts like maybe that person is with someone else right now, kissing and hugging and maybe fucking all night long. These are all abnormal thoughts. Gosh. When will I be able to grow up and just don't give a fuck about all these things? If that certain someone wanted to do all that, there's nothing I could do to have stopped all those from happening. Maybe it's time to just be single and shut myself out from all the relationship possibilities?

Here are the self-deceiving reason why I should stay single:

1) Nothing to be worried about

2) No one to report to

3) I can go with whoever I want

4) I can go anywhere whenever I want to.

5) No imaginations and hallucinations

6) Nothing to expect and nothing to be disappointed at.

7) You're in charge of your happiness

8) You sleep more soundly

9) You have richer friendships

10) I can love myself more

Well, who I am trying to kid? Who doesn't need a life-long partner? 

But to be questioning the other party all the time is really tiring and a waste of time.

Hopefully one day i'll be on level 100 to just don't give a fuck about everything.