I'm not sure seeing a Doctor would help a great deal in this situation. I take it that you'd already been diagnosed as dysbraxic?
To me it sounds like that the stress of the pressure that you're under at work (much of it generated by yourself) is affecting your ability to cope.
You've already indicated that actually you're a pretty smart invididial and that's important to remember, that you're not stupid nor daft yet you may need a little more time or slack to achieve your goals.
Explain to your boss/tutor/head chef (what ever it is) that you have dyspraxia which (in laymans terms for him) manifests itself as a learning difficulty. It affects your ability to concentrate, interept messages and multitask. Explain that the pressure you feel to complete thing quickly to a high standard is affecting your ability plan and methodise your work.
Then maybe together you can sit down and work out main areas that you struggle and formulate a strategy and working method which you need to learn as second nature
I think one of the largest problems you have is that you expect too much of yourself and this results in you not using the ability that you do have because you're in panic mode too much. You need to take a step back and say "ok, I can't do it like this because x,y&z. But if I can do it my way, it'd still be pretty good!"
That's the positive bit of advice for if a catering career is what you really want for your life, the following paragraphs are a little story about myself.
I used to be an aprentice mechanic, and this was one the worst environments to be in for me. None of my mentor technicians knew I had Dysbraxia, none of them probably even knew what it was. What it's clear they did think is that I was slow, daft, stupid and basically incompetent. They were incapable of appreciating that I had a genuine difficulty that had nothing to with intelligence and were basically just very inpatient with me, condescending, thought I was weak and cack handed and basically had no confidence in me. Looking back it's no wonder why I had no confidence in myself under these conditions. I was slow to learn how to do relatively simple jobs, would forget instructions by the time I'd got to the other end of a car and basically just really struggled to hold any useful information in my head.
I expected too much of myself, I didn't allow for that maybe just maybe I simply wasn't cut out to be a mechanic. I felt stupid, I had even less confidence in myself than the others had in me, my self esteem was none existent. I was utterly miserable and boy was I frightened! I think I got a little too close to mental breakdown, I had already decided by the time the final incident at work happend that I would not be completing my qualifications and would be leaving the job probably around the time that year at collage finished. But in the mantime I had to stay to earn some money. Then one dreadful day when I made some fairly fundamental mistakes because I was putting myself under too much pressure and my mentor mechanic finally lost and I mean really lost his rag with me.. after that I simply could not face going back into work. The management were actually incredibly supportive, I was not sacked, I was actually paid for a couple of months after leaving the job.. but I simply could not subject myself to the torture handed out to me by my immediste colleagues and above all myself any longer.
Now.. That may sound negative and defeatist. But I was moving towards making myself ill. By leaving the job I was coming to terms with the fact that I had some limitations. I learnt an incredible amount about myself and others. A lot of the stress was lifted. The most important thing I learnt was that I alone know what I can or not do, and I will not be forced by peer pressure into things or areas I do not want to be. I know that I'm quite intelligent..even if I sometimes struggle to show it, I know that I'm unlikely to demonstrate my intelligence at an acemdemic level.. But I do know that I can apply method and sense to my everyday life, ultimately it doesn't matter what other people think becausse only I know, and I know enough to get by.