Trouble with CPU and Slow Windows After Cleaning My PC

I have an ASUS ROG Strix B450-F Gaming motherboard, Trident Z RGB 16GB RAM, a Ryzen 5 3600 CPU, and a GeForce RTX 2070 GPU. I built my PC in 2020 and it sat unused for the last couple of years. Recently, I cleaned it out and removed lots of dust, including the CPU cooler. When I took the CPU out, I had to remove the old thermal paste and reapply new paste. Some pins were slightly bent, but I managed to fix them. Now, when I put everything back together, there's an orange light on the motherboard, and it won't POST with both RAM sticks in the A2 and B2 slots. However, it does work with just one stick. Once I get into Windows, it's incredibly slow, to the point where Task Manager crashes. This slowness was also an issue before I stopped using the PC. I can see both my HDD and SSD in the BIOS while booting from the SSD. I'm wondering if I need a new CPU or if there's something else I should check. I've tried various troubleshooting steps like clearing the CMOS battery, reseating the RAM and GPU, but nothing seems to help. Any suggestions would be greatly appreciated!