Spontaneous bootloop can't get out

[AC Question]

Hi! A couple of weeks ago I let my Galaxy S5 (G900F, Dutch, Vodafone) auto update to lollipop. Problems within a week (spontaneous reboots for instance). Then today my phone went in bootloop. Couldn't get out.
So I started reading/googling: The advice was to use odin to reinstall the latest lollipop version (I check for the G900F one ). Didn't work; still bootloop (with the difference that it had recovery boot or something in the topleft part of the screen). So then I tried installing an older (Kitkat) version: Odin (v3.09) gave out a FAIL. I tried both the kitkat (4.4.2) and the lollipop versions multiple times.
Then I read that I should use a CWM (again, checked for the correct one) and then I get the 'seandroid' message, and then it bootloops again.

Sorry for the wall of text but I just want to get my original lollipop (or preferably kitkat since I liked that one better) back...I don't even want a custom rom

Oh and just to be clear: I can't get into the recovery mode (power, home and vol.up); it just gives me the 'bootloop' screen. I can only get in the download screen (power, home and vol down),

Thanks for your help!