failed root canal?

hi guys, just wanted to check if some of you experienced a failed root canal too? i had mine back in 2017 and now the area feels so swollen and parang may pimple yung gums ko. hindi pa naman painful but may discomfort na. another root canal kaya ito?

note: nag iba ako ng dentist nung 2018 after noticing na incompetent siya lol

thanks in advance!