yes, you can use di chan in formal situations .
in formal term
can also use
kha pa jao, kha pa jao aeng,
dian(เดี้ยน) This word is short word of di chan
otherwise you can also use
can aeng ข้
Tua chan aeng
Khao ( khao,litery means him/her), but can also express as i, myself.
Lastly , you can repeat your name instead of useing any of all above. This also works!
Hope it helps.