In french, continuous tenses are translated by “être en train de”, so your examples become:

1. J’étais en train de me faire tuer
2. J’étais en train de me faire intimider
3. J’étais en train de passer un merveilleux moment

Note that number 3 is very different from number 1 and 2. In 1 and 2, it is a passive form, so in french, you could also say :

On était en train de me tuer
On était en train de m’intimider

• If the context makes it clear that you are not talking about a habit but about something you were doing in a precise instant, you use the imparfait:

I was having a good time -> Je passais un bon moment.

This morning I was having a drink when… -> Ce matin, je buvais (une boisson), quand…

(as "boire" contains already the idea of drinking, you don’t have to repeat it by "boisson", however if you want to insist on it you can)

Just when I was being bullied, the teacher arrived -> Au moment précis où je me faisais brimer, le professeur arriva. / A l’instant où on me brimait, le professeur arriva.

(Passive should be avoided in French)

• If there is a risk of ambiguity, you can be more precise with the use of "en train de":

I was having a great time -> J’étais en train de passer un moment formidable