Whilst I don't have the mechanical skill to do what you've done, I'm kind of feeling the same with mine. Spent about 4k on upgrades. Enjoyed it for all of 2 weeks before I pulled out on a fast moving island and the car left me stranded in the middle of it with traffic speeding towards me. That was April. Since then its been in the garage every week or every other week. I've spent about £800 changing parts and diagnostics (no error codes) to the point the garage won't take my money any more. Removed my map (£340 wasted) + £60 to flash to stock. Now gotta pay £400 to get it mapped again. After changing everything mechanical it could be, it looks like I've finally nailed it to an electrical fault. Fingers crossed... cause I'm still really nervous driving it.
My point being is, I laugh to myself because the garage at one point had done more miles in my car than I had (they do a test drive every time it goes in). I was in the autotrader looking at cars. But personally, looking at what you've done so far to your car, its damn impressive and have said so before. I think you should stick with it... even if you have to take a break for a couple of weeks and regroup. And from the sounds of it, you already have the parts to fix it?
My point being is, I laugh to myself because the garage at one point had done more miles in my car than I had (they do a test drive every time it goes in). I was in the autotrader looking at cars. But personally, looking at what you've done so far to your car, its damn impressive and have said so before. I think you should stick with it... even if you have to take a break for a couple of weeks and regroup. And from the sounds of it, you already have the parts to fix it?