So the thing about my "HDD-Problem" is that every HDD i plug in is starting out with normal speed, but after about 2 weeks I hear when the disk is working and the sounds... well it doesn't sound too good and also the speed is noticeable lower than before. On other PCs they work as they should, therefore the HDD itself is not the problem. (Neither PSU or SATA Cables/Slots)
But to be honest i want to get away from HDDs anyways so this is not the main reason.
I'm more focusing on if it makes more sense to like save up for a new CPU and motherboard instead of buying a motherboard for my current CPU.