If the performance is the same after upgrading it might be your internet connection or one of the internet routes you travel on from your workstation to the DigitalOcean datacenter where your droplet is located.
I would do a few things now:
1) Check the graphs for your droplet - is there anything out of the ordinary in terms of Network or CPU consumption? If the graphs are all low then it’s probably not the droplet.
2) The net::ERRSPDYPING_FAILED 200 might be related, it looks like an older feature of Chrome browser. Have you tried restarting / updating chrome lately? If you google that error there are a few recent posts on the net that describe some different troubleshooting steps if updating doesn’t help.
3) If that doesn’t seem to help, some other suggestions involved flushing the local DNS cache on your computer.
4) Ask co-workers or friends to check your site and see if it is also slow to them - or try yourself from a different device and internet connection.
Good luck and let us know how it is going… feel free to ask more questions as you run into them.