Try these Things and Your Problem Will be Solved
For me, the database optimization worked because I had the database of the size 200MB, but it should be only of 44MB.
It may be the case for you, too. If you have never cleared the used database tables, tables created by the deleted posts, extra metadata, etc., you should try clearing them.
And a CDN can help you a lot in general. Even if you don’t face any problem, you should enable a CDN on your website.
I mean who doesn’t want his/her website to load fast? Well, you should think about it. You can try the free CloudFlare CDN, or you can go for the premium once like MaxCDN.
And having a cloud hosting is always a plus point.