It has happened three times to me many time while meditating and since the first time I knew I had felt it before; I remember having this experience a couple of times throughout my life while trying to sleep and having to wake up and drink a glass of water or something so it would go away because I didn't consider it pleasurable, however, now I'm meditating I think I shouldn't label it so I just went through with it despite my fear and felt it for a couple of minutes.

The experience itself can be described as if I was getting distant from my surroundings. I have a fan in my room and I can hear it while meditating when it's on, it somehow felt like the fan was hundreds of meters away and everything including the walls, the door, the bed just kept getting further away. I wouldn't say I felt I was floating but for a moment I did felt distance from the floor as well. Now you can understand why I wanted to avoid it in the past, when I was little I felt my mothers room getting away and I was scared that if something happened she wouldn't be close to me, also it felt like the beginning of a nightmare.

It happens when I start by focusing on my breath and after I calm my mind I try to keep it free from thoughts while not focusing on anything; particularly during this "focus on nothing and think of nothing" phase. Also, I meditate with my eyes closed, this is not a visual experience.

This experience is too nebulous and vague to match with what others go through.  The boundless space jhana sounds similar to it but not exactly.  All you had was an altered state that is temporary.  

Another thing.  "Focus on nothing, think on nothing" doesn't really happen.  The intention to pay attention, the intention to meditate, the intention to follow the guideline "focus on nothing" is all objects for consciousness/knowing/awareness to know.  

If I were you I would find out what my goal was with meditation and follow real mediation practices that yield results.

All right, thank you. Currently I practice Anapanasati and I think I'm close to access concentration, that's my current goal. There are days that I feel like trying something different like Kasina, but it's probably better to stick to one type and advance in it.

You got the right idea.  Continuing with the same concentration practice will be mean that the skill will condition itself and get you to jhanas.  If you jump to different practices all the time the brain will always be at the beginning.

The only thing I would add is a metta practice because it can get you in a good mood which helps with concentration practices.  Also notice how letting go of thinking (including thinking about the practice) and increasing the gap between thoughts will gradually feel more restful than thinking habits.  Eventually the brain will just want to let go further and the mind will absorb with the breath/kasina/object of concentration.