How to repair broken EFI partition

Hello everyone, I'm going to need some help to repair my broken EFI partition. Also, expect some grammar mistakes since English is not my first language. 

So, I recently bought a second hand Dell Inspiron 15 7567 gaming laptop, the model that has an I7 7700HQ and a GTX 1050ti. It came with an 256gb SSD and a 1tb HDD, the previous owner did not upgrade any of the components except for the RAM which he only added a single 4gb stick to the stock 8gb module. The laptop was formatted with windows and its usual EFI, system reserved and recovery environment partitions aside from the main windows partition, but also the Dell SupportAssist recovery partition.

Turns out that, every now and then support assist would come up, do a quick scan and then either freeze or shutdown the computer, then the laptop would boot normally, this wasn't common at all, but that was only until I completely wiped the SSD, installed both windows and Linux on it, that was my mistake, I only did that, I never tried to configure or check if the efi partition was fine and I never cared for the oem recovery tools, I just figured the windows installer would do everything for me, and it that should be the case but I remember something weird happening, you see, at the time I was formatting the drive, if I selected the main partition to reinstall windows on it, the efi and the rest of the the usual partitions showed up, however, when I did the full wipe, only the system reserved partition was there, not the EFI.

Now, normally, this would cause an unbootable system and I would have to manually create the EFI  partition, but it just so happens that the HDD also had a EFI partition that I suspect the windows installer automatically detected and copied the boot files to, and not only that but also grub did the same when I installed Linux, thus making my system kinda work with an EFI partition on the secondary HDD and everything else on the main SSD, my entries on the boot menu at the time of the bios were as follows: Windows, Linux and a partition I didn't recognize on the secondary drive (probably the efi one), I did not know this was possible.

Up to now, I've been booting into the SupportAssist scan I mentioned earlier everytime I used the laptop, skipping it by aborting the scan and turning on the machine again, then using it as normal, this worked for me so I just figured I would someday fix it, which turned out to be a very big mistake. The real trouble began when I used my computer to fix another laptop by testing a bootable pendrive on it, the exact trigger was probably when I accidentally booted the third entry on my boot menu thinking it was the USB drive, after that, the other two entries were gone.

The SSD is still detected, I can boot into Kali Linux on a live usb session and browse it, the bios settings also detect it, disabling or even physically disconnecting the secondary drive results in no entries on the boot menu, booting into the third, now only, entry just gives me a windows blue screen telling me that my system can't boot (Error code 0xc000000e) which is obviously very useful, my previous working and also current boot mode is UEFI with secure boot disabled (because of Linux), I have RAID on instead of AHCI (was like that by default) and by browsing said partition with Kali Linux I can see that the files are there. 

Things that I have already tried:

* Switching boot modes

* Disabling legacy boot

* Restoring BIOS settings 

* Letting SupportAssist do a full scan (results in it telling me that I should wipe out the ssd and start over again, it's slowly convincing me to).

Things I think should work but haven't tried because I fear of breaking my system any further:

* Switching from RAID on to AHCI

* Making another partition on the SSD using gparted, moving both the windows and Linux from SDA2 and SDA3 to SDA 3 and SDA 4 respectively, and either cloning the secondary driver's efi partition there or build a new one (I think this will only break Linux but I'm not sure, my question is, does efi HAVE to be before the OS's partitions or not?)

So, that's the problem, I don't want to try any of the above because I have some files that don't have a backup of, so if any of you have any idea how to fix this mess, I beg of you, please post them, I will answer every question you have about my system and post Screenshots and photos accordingly, so thank you in advance, and again, sorry for making you read such an essay written in my broken English, I will also appreciate any corrections you make.