There are many tutorials on the net about using an ESP8266 to send temperature & humidity data to Thinkspeak. Try this one in the first place to see if it works for you. Furthermore, the code is quite simpler than yours 
There are many tutorials on the net about using an ESP8266 to send temperature & humidity data to Thinkspeak. Try this one in the first place to see if it works for you. Furthermore, the code is quite simpler than yours