How to take care of panic attack during defence

I feel nervous in losing positions and in winning positions lol.

I like a small drink of alcohol, like half a bottle of Champagne or a whisky but don't forget we live in a much colder climate and so we are often physically active. Except for all the fat ones that live here.

I used to feel so nervous in difficult positions I couldn't handle it. It took about two years to learn to control it. You just have to force yourself to think. Taking a walk in the middle of a game used to help. It was worth losing ten minutes on the clock.

My advice is to play the board and as @optimissed  had said create traps on losing position 

That's a great suggestion and i definitely going to used and apply it. 

You have described  the symptoms, the factors and how to deal with the symptoms. 

But something is still missing like I don't know how to calm down,  breath normally and i just don't tinkle  enough to learn about bad position. In daily chess, because of ample time to play the moves,  there it is possible to develop defensive skill because you can analyse the position for the whole day and do in your disposal whatever the resources is there. If you are too demotivated,  go other the house and stroll on a nearby town or park.   In this way you can forget the pressure and stress for a brief interval of time. And thereby when you return to the house,  you can make the moves afresh. 

I would recommend you to play chess otb as much as you can, at different speeds. five minutes per game, ten minutes, twenty minutes, half an hour, one hour, one and a half hours. For instance most club chess in the UK is played at 90 minutes each for all of the moves whereas tournament chess is often slower, with 2 to 2 1/2 hours. At the club most weeks, I prefer to play 20 minutes per game for each player. I'm best at fast speeds, say 10 minutes, and very slow speeds. I like 2 1/2 hours for all moves very much, but only for a graded or rated game when I am playing someone my own strength or stronger, because otherwise it feels like wasted time. I dislike the Fischer clock which adds on seconds and turns the game into a farce at the end.

I would also advise you to take part in an over-the-board tournament with about five games, if you haven't already and if they're available where you are. Just one tournament if need be but focus on it completely, take exercise between the rounds, get sufficient sleep and so forth. And try to program yourself to focus whenever you are playing with a clock and writing your moves down. That should put you in a special space where playing chess is the only thing you're thinking about.

It is certainly less expensive to play in a local chess club than in tournament. Also,  the environment is going to be much more friendly in a club and that's what i really care. But the competitive spirit of tournament is also very much appealing to me.

I create traps all the time, or at least I try...

Haha,  good for you. I have to look at some of your games in where you were losing but managed to put up a brave fight. 

Well, you could try playing over-the-board friendly games to have a feel before jumping straight into "the lion's mouth" (your local tournament).

You just save me from becoming a good joke. 

I once had a very unfortunate panic attack in a game. I was up a pawn in a game in a very comfortable winning position and quickly played Qa4+ trying to win a knight on b4 after calculating some lines. Soon after I realised that this knight was defended by...the very bishop on f8 from the starting position! I subsequently panicked and my position deteriorated all the way.

It was my only loss of the tournament (in which I drew the first three games, lost this fourth game and won the last three) and it was really saddening. My opponent afterwards asked me regarding my decision for making the move Qa4+, and I told him it was based on a miscalculation as the knight was already defended.

To make things worse, he used to frequent my chess club and I have never lost against him in my prior encounters (I had won him in all encounters before this loss).

In my case, I "meditated" for two or three minutes. Somehow that worked in my won games and almost worked in my "lost" games against players rated 600 points higher than me (I suddenly missed the winning blow in a time trouble generated by my own meditation).

Walk around for a few minutes, take in some deep breaths, go splash some water on your face, anything.  Restore equilibrium and go back and play well.