Yes, have been stuck in such issue. But luckily to solve it ,here i am glad to share the methods with you.Hope it caan help you.
First, disable Hibernation:
The Hiberfil.sys file almost take a same amount of space as the random access memory (RAM). So it is better to disable it when your SSD runs very slow:
enter the command prompt window by clicking the Start button and type cmd (please run as administrator), and type command powercfg.exe /hibernate off and press Enter.
Seond, make SATA controller runs in AHCI mode
AHCI (Advanced Host Controller Interface) Mode does a fabulous job of keeping the high performance of solid state drive. So when it is disabled, the SSD might run slow and take a very long time to respond. It is better to set your SSD mode from IDE to AHCI.
1) Press WIN+R and type msconfig and then press Enter.
2) Under Boot tab, tick Safe boot, click OK to save the changes, and reboot your computer into safe mode by constantly pressing F2 or DEL. Change your SATA mode from IDE to AHCI. Then save settings to exit and reboot.
3) Windows will boot in safe mode this time. Run msconfig again, and untick Safe boot option Boot tab under and restart your computer.
If you tried these two methods but the problem still unsolved, you can try to align SSD partitions to improve the performance, or completely erase the disk to restore its peak performace, to get rid of
ssd slowing down.