I'm an intern at a workplace where they are heavily into this LGAT thing called 'PSI Seminars.' LGATs are cult like I suppose.

I tried to complete the PSI Seminars basic but ended up feeling very unwell and going home the second day.

I ended up catching a cold. Didn't go to work for a week.

Since I have come back, things have fallen apart. I was being considered for temporary work for November and part of December. They had been telling me this since October 6th.

Well, not anymore. They just replied with, 'Oh, we found someone else.'

A couple of people who were incredibly nice before treat me like a pariah. Like they're annoyed to even see me.

People avoid me now. Most people in the office went through and finished PSI Basic.

I'm sad because things were looking up, and they came crashing down. I only get 80 hours for this internship, and I might just spend the rest of them just sitting at a desk doing and learning nothing. I'm like an afterthought now.

I know I have no future there. And when this internship ends, I will not have an income stream from an additional source.

I suffer from depression and I feel myself going to a deep dark place.

I'm sorry you're having these life difficulties.

I ended up catching a cold. Didn’t go to work for a week.

Assuming your work schedule puts you in the workplace 5 days a week, I think you calling out is having the negative impact you're seeing, not because you haven't completed the PSI Seminars. Unless you have other health conditions complicating a cold, being out for 5 days for a cold feels excessive. A day? Sure, no problem. Two days? Probably okay. Three days? Borderline at best. Four days? Employer would be asking "what kind of cold is this?". Five days (which likely bled into 2 more days for the weekend). "I'm not sure we can rely on this person going forward".

Again, if you've got other health issues where a cold is a much bigger deal (such as being Immunocompromised, as just one example) then 5 days out for a cold could be entirely reasonable. However, those challenges (and requests for accommodation) need to happen when you're hired, and not after-the-fact when you've had a 5 day absence.

I know I have no future there. And when this internship ends, I will not have an income stream from an additional source.

Since you posted in "Advice", I assume that's what you're looking for. My advice would be to reach out to your manager and take responsibility. Let them know that you're still learning and that even if it means you don't have a future with that employer, its important for you to learn and any actions or advice your manager would have for you would be welcome even if it is critical of you. If they say things you don't like to hear, be courteous, be professional. Thank them for being honest with you and let them know you're committed to learning from this and that you're receiving their criticism constructively.

Good luck!

It's not uncommon for the cold or flu to keep someone out of work for a week. It's happened before.

It’s not uncommon for the cold

It IS uncommon for the cold to keep someone out of work for a week.

or flu to keep someone out of work for a week.

Influenza is a much more extreme disease. That could certainly take someone out of work for a week. You didn't say you had the flu. You didn't tell your employer you had the flu. You said you had a cold.

Yes, a severe cold can keep someone out of work for a week, as symptoms can last up to two weeks for some individuals, and the most contagious period is in the first few days. While many colds resolve within a week, those with more severe symptoms or who are taking longer to recover may need to stay home longer. Staying home protects colleagues, especially those with weakened immune systems.
When to stay home
When symptoms are at their worst: It's best to stay home when symptoms like fever, fatigue, and aches are most severe.
If you have a fever: The CDC recommends staying home until you have been fever-free for at least 24 hours without the use of fever-reducing medication.
To prevent spreading the virus: You are contagious for the entire duration of your symptoms, which can last one to two weeks. To protect others, especially those at higher risk, stay home until symptoms are improving overall.
What to do when you return to work
Go back when you are no longer feverish: You can return to work when your symptoms are improving and you've been fever-free for at least 24 hours.
Wear a mask: If you must go back before all symptoms are completely gone, wearing a mask can help prevent spreading the virus to others.
Be hygienic: Wash your hands frequently, cough or sneeze into your elbow, and avoid close contact with colleagues.