Okay, I've tried different solutions: ENB Series, removing certain mods, checking my FPS Rate, monitoring my resources, .ini tweaks. It's all just fine, I don't see what I'm missing.
A couple of days ago, I bought Skyrim. Before I bought the game, I admit I had a pirated copy because my girlfriend actually wanted to buy me the game as a present, then said she didn't have enough money. Sick of waiting, I decided to buy the game by myself. The ridiculous part is, it worked better cracked than it does now uncracked.
As the title suggests, after entering and leaving houses a couple of times, my performance obviously drops extremely. My build is just fine, Intel i5 quad core processor, NVIDIA GTX 560 Ti from Gigabyte, actually stock-OC, but manually downclocked to usual settings using appropriate Gigabyte software. This fixed the CTD issues I had before with both Skyrim and BF3. I have 4GB RAM. A website about Game Tweaks suggested that my HDD may be too slow. A screenshot of a Windows Performance Index sample with the subscription "This is likely to cause issues" showed the HDD with a performance index of 5.9, the exact same mine has, so I was playing with the thought to purchase an SSD instead, load games onto it that really need it like Skyrim, and hope it'd do the trick. Unfortunately, SSDs are likewise expensive, compared to "normal" HDDs...
I'm really getting desperate about it. My save is gone because the patches made it impossible to load saves of the unpatched version and I already saved more than 80 times despite being only level 8, just because every time I interact with a door leading me to another location I'm scared the game will drop again. I can't even play for 30 mins straight anymore, it's just no fun at all.
I've researched for a couple of days before I decided to post my question here. Any help is appreciated, I don't want to regret having bought the game... Since it actually is the best game I've played possibly for ever.
Sincerely.
P.S.: I don't think it's necessary to say, but still, of course I'm playing on PC.
P.P.S.: After monitoring both my PC resources including CPU usage and HDD usage as well as the GPU usage, I don't see any changes even after the said event.
P.P.P.S.: Original question posted here where I've been advised to ask here.