Hello everybody !
First of all, let me introduce myself. I am a student of 23 years old and come from switzerland. I have been practising meditation for about 2 years now almost daily. I am very happy to have found this forum because every french forum I visited so far were dead (never any answer). So let me appologize because there might be a few gramatical errors, and it's probablly going to be a very long post.
I first came to meditation trhee years ago, by trying a Vipassana retreat of 10 days. I wanted to be able to calm my mind that was (and sometimes still is) continuously building imaginary scenarios about anything that was quite tiresome.
But taking into acount I didn't know anything about meditation (thought I would have some vision and "fight my deamons" litterraly) and didn't realise my deamons were : impatience and lust of new experience, I only could stay for 1 day before litteraly break up from anger and left the retreat. The fact that I have trouble with authority was also a big point because we were "forced" of meditating even when we whished a pause.
I still noticed a few benefits when leaving so I decided to try it less harder at home.
one year later I started to practice seriously (about half an hour a day). And started to understand what meditating was really about.
My problem is, I don't know anybody who could give me theoretical advices, and sometimes I ask myself what I could do better to meditate "deaper". This is why I come to you dear reader.
My main problem is sometimes to keep focus.
Sometimes I don't have to force it and I can wheather practice a "goenka style" meditation being totally focused on my breath, or even easier practice a "mindfullness" = "accept and observe everything that presents in the moment". And I whish I could meditate like this everytime.
Some other times, It's really hard to get into it and sometimes I can't even meditate. I sit, and start to try focusing on my breath but then, I keep observing my breath but my brains starts to observe it as a parralel task and is mainly into my inner chatters. As if I could observe myself (at least a part of it) and at the same time thinking about lot of things.
The thoughts that disturbs me the most are the ones that are analysing what is actually going on right now. Is this the present moment too ? because some thought might be : "oh you are again thinking about what you are thinking, so now stop thinking but now I am thinking that I have to stop thinking". So in a way I seem to observe my thoughts as everything else. but this doesn't calm me as if I stay totally in emotional and physical senses without bringing the mental into it.
So I would like you to exchange with me a few tips you have to entirely dedicate your mental to observation of the other parts of being, because I feel that observing the mental with the mental makes like an "infinite loop"

informaticians.
I tried to observe with the heart the mental but in this case I totally lose control and don't even notice that my mental has gone and I start thinking about things that have nothing to do with the present moment. The only thing that seems to help is doing sport before or start with hypnoses (on youtube).
I now am thinking to do a Viapassana retreat again, but the kind of meditation they practise "only focus on breath and nothing else" seems a bit counterproductive to me because it fights against natural pulsions and emotions we have instead of noticing them and escort them to liberation.
To resume :
- how to calm the mental in the beginning of meditation so it doesn't spend the next half hour to observe itself.
- is thinking about present thoughts living the present moment ? or is it already thinking ?
- any tips for this ?
- Is it a good idea to start Vipassana again taking into account I didn't last 2 days last time ?
Thank you a lot for your answer and wish you the best.
PS : I am a heavy maryhuana smoker (but never before meditating), could this lead to concentration problems ? (I don't have any concentration problems in other aspects of my life)