First of all, relax!!!
History: The IB history course is absolutely different to the IGCSE course so you won't be at a disadvantage if you end up choosing it but you obviously may be lacking a little background knowledge. That however shouldn't be a problem as you'll be taught everything that is required for your IB exams etc during the course of the 2 years. Since you seem so interested I definitely recommend you take it as having interest is one of the main thing that will enable you to bare the intense 2 years. Do keep in mind that history is a really a hard IB course, though and getting a 7 is quite rare. Nonetheless, if you are excellent at memorising a bunch of facts and can write coherent essays you'll be fine.
Chemistry: Firstly, doing well in IGCSE chemistry doesn't guarantee you'll do well in the equivalent IB course as the IB chemistry course is much harder and requires a lot of dedication and hard work to get by. On that note, don't take chemistry if your not interested the slightest as you'll regret it (basically take history instead as you'll be doing yourself a favour by taking a subject your more interested in). Secondly, you mention wanting to go into psychiatry (a sub speciality in medicine (which your clearly not aware of)) in which case you must go into a medicine course to become one (you specialise later on). In case your not aware you MUST take HL chemistry to get into medicine in the UK so there is no way you can achieve your goal to become a psychiatrist without going into medicine. Therefore, if your still interested in psychiatry you've got to HL Biology + Chemistry as well as SL Maths (beware studies may be looked down upon, you need to confirm this by emailing unis though). However, if your mixing being a psychiatrist with a psychologist (which do research, counselling etc but don't prescribe medicine, psychiatrist are the ones that prescribe medication) then taking HL chemistry is unnecessary as psychology course only require HL biology.
Arabic: Seeing as your fluent in arabic you might consider taking it as a HL subject if you want an easy 7 but some unis may frown upon this if they realise it's your first language as you
should be taking it as an A1 course. However, it's actually not that easy of a course if you're not fluent in fusha (or whatever it's called). I live in Saudi Arabia and many of the native Arabs still struggle with the course but they suck so don't take my anecdotal reference too seriously. I've lived here for around 13 years and don't speak much but can write a bit and have been allowed to take B SL so I think you taking it would be cheating the system.
Have you considered taking french?
English Literature: Not haven taken literature before IB shouldn't pose as an issue as the depth of the course will be knew to everyone even those who've taken IGCSE literature. I'd know because I was in a similar stance this year as I wanted to take literature despite not taking it as an IGCSE subject. My teacher assured me that it's completely different and that if I work hard enough that I'd be able to do well. Don't let the fact that you've never taken literature before stop you from pursuing the IB course. Plus, you've go the added bonus of having your mom at your disposal to help you out whenever needed.
Basically, take history over chemistry* and take literature.
* Indicates that you must choose chemistry over history if you want to become a psychiatrist and not a psychologist.
For Psychiatry:
English Literature HL
Biology HL
Chemistry HL
Maths SL
Language (up to you)
B&M or History (both equally hard subjects, history however isn't considered to be a soft subject but since your HL subjects are hard as is, take the one where you think you'll obtain a higher score)
For Psychology: Option 2
English Literature HL
Biology HL
History HL
Maths Studies SL
Language SL
B&M SL (better as an SL subject since it's soft)