(An/The) Earthquake in Mexico

Last night there was an 8.2 magnitude ('an' because the next word is 8, not because of the word earthquake) earthquake of about 8.2 degrees richter in Mexico. The epicenter occurred was (located) in the south of the country. I was lying down (o.. lying on the sofa), watching television when suddenly everything started to move shake (mejor), I was a little scared a little because I immediately remembered the great earthquake that happened in the city of Mexico Mexico City in September 1985. I was not yet born (I wasn't born yet suena mejor), however I have seen on television all the damage it caused.

Specialists say that there will probably be replicas aftershocks, so we must (have to suena mejor) be prepared and follow security protocols.

Thank you in advance for reading this.

También, he experienciado un terremoto pero solo fue 5.5, y aún eso sentí fuerte.. cuídate cuate!

Earthquake in Mexico

Last night there was an earthquake of about 8.2 degrees richter in Mexico, . [1] The epicenter occurred  was located [2] in the south of the country. I was lying [3] watching television when suddenly everything started to move, . I was scared a little because I immediately remember remembered [4] the great earthquake that [5] happened in the city of Mexico in September 1985, .I was not yet born, however I have seen on television all the damage it caused.

Specialists say that there will probably be replicas [6], so we must be prepared and follow security protocols.

Thank you in advance for reading this.

[1] an 8.2 magnitude earthquake in Mexico. (This is a better way of saying it. Also, most people will assume the strength of the earthquake is being measured on the Richter Scale, so this info isn't necessary.)

[2] It sounds strange to say that an epicenter occurred, as an epicenter isn't exactly an event.

[3] Usually when we say we're lying down, we say "lying in bed" or "lying on the couch." It feels a little like information is missing with the way you have phrased it.

[4] Past tense is needed because you are describing an event that happened in the past (as in, you remembered this last night as it happened).

[5] You need to use "that" here to tie "earthquake" and "happened" together.

[6] Not sure what you mean by replicas - do you mean more earthquakes? If so, the word "aftershocks" is appropriate.

ALSO, please remember to use periods where needed instead of commas. You only used two periods here! I will assume that you know how to use them. :)

I hope you stay safe!

Earthquake in Mexico

Last night, Mexico was struck by an 8.2 magnitude degree earthquake on the Richter scale, the epicenter was located in southern Mexico. I was lying down and watching television when suddenly everything started shaking.  I was a little bit scared because I immediately remembered the great earthquake that happened in the city of Mexico in September 1985; I was not yet born at the time, however, I had seen all the damage caused by the earthquake on television. 

Specialists say that there will probably be replicas, so we must be prepared and follow security protocols.

Thank you in advance for reading this.

Great job!
I hope this helps

Casey