Making multiple clips out of one longer clip the fastest way?

[Aûreon]

Hello

So I'm feeling a bit under the cloud here with this issue. I'll try to explain it as ELI5 as much as I can so everyone can understand it perfectly.

Let's say that I got one 5 hour long clip which I want to make multiple shorter clips off. For example, ten 30 minute clips. And then I want to upload them to YouTube, which I can do through Premiere.

The way I proceed with this matter is the following, in detail.

1. I first press I to Mark In where I want the clip to begin.

2. Then I change then time on the timeline from 00:00:00:00 to 00:30:00:00

3. Then I press O to Mark Out where I want the clip to end.

4. I've now marked 30 minutes of the 5 hour long timeline. So I press File, then Export in the top left corner.

5. There I change the title to for example "Episode 1" and add a thumbnail with the number 1 on it as picture for example.

6. I then press Queue and It's added to Media Encoder, waiting for the rest of the clips.

7. I then press I to Mark In for the second clip.

8. I then change the time on the timeline again from 00:30:00:00 to 01:00:00:00

9. Then I press O to Mark Out for the second clip.

10. That's the second 30 minute clip marked. I go to File and Export and then change this to Episode 2 and add a second thumbnail with the number 2.

11. I then press Queue to add it to Media encoder.

Then I continue doing so until I've made clips out of the entire 5 hour long timeline. Now let's say it would be 20 hours long. Then It would be quite a tedious process.

What I'm wondering is, is there any feature I'm unaware of? Or do I have to do all of this manually like how I described? Or is there any automatic way of doing it faster?

I'm very new to this so I don't know really what to do. The method I mentioned works, but it is taking a toll on the sanity after a while.

Thanks in advance