Can too many tags make wordpress site go slow?

I have a wordpress site with 5000 to 6000 visitor per day. I have dedicated vps hosting 2 GB RAM 2 CPU Cores 4.8 GHz Total CPU Power 80 GB SSD Disk Space

but it is too slow at some point. even sometimes it says busy. when i check using c panel it shows all ram and processors has been used with red mark alert sign.

I haves used too many tags on most of my post is it because of that "am guessing". As,once I made one post with nearly 1000 tags, while posting it, the whole server was down so i have to remove the half of the tags. I have many post with almost 200 to 300 tags on it.