get a dog....
... to chase you at that 1km mark LOL

Kidding a side.

You have been running for 4 months so your muscles will be tone unless you still have sores or injury.
If sore or injury then healing and resting takes precedence.

In good shape, here is a tip to run continuously for 10km.
For me, I have to go back to finish up my laundry so i keep going.
You have to find your dog to motivate yourself.

Here is a technique.

What you can do is in your first 1 km, once you are running at your natural pace,
Pace your run:
Slower when you want to... or maybe for 30 seconds.
Faster when you want to... or maybe for 30 seconds.
Natural pace.... for 30 seconds.
Repeat in cycles.

Once you can pace yourself, when you feel like stopping but have 6km to go then...
slow the pace where your body can catch the breath you need.
Then return to your normal pace.

When you begin to feel tired or need to slow down, then slow down your pace.
When you slow down, let it happen naturally so you use less energy.
If you slow your pace deliberately and still using more energy then keep practising until you can slow down naturally.

When you are tired in your final km, think of your bladder.
You should be able to run to the lavatory faster to finish.

Hope these tips work for you and remember to get a dog, have fun.

I will relate my experience and you can give it a try to see what works for you.

I walk to my spot, that gives me a benchmark.
In the beginning I pick up to a pace, until I get the flow.
Flow here I mean that it feels natural for me. Not over exerting or too slow.

Find your flow, then notice your cadence.

You want to run 7km at optimum speed non-stop = Goal.
You have 4 months track record and fitness level = Capability.
What is stopping you from your goal are two factors:

1, You are not employing your capability well; maybe you keep pushing speed at the expense of stamina?
2. You lack skill; deliberately slow your pace instead of relaxing your pace.

My suggestion was to build your capacity in pacing / relaxing your pace.

You made a good point, you sped ahead and unable to monitor others.
So the race is with yourself. Find your flow / cadence that will achieve your goal.

I have a new suggestion for your consideration.
Heart is a muscle. The most important muscle.
Have you train your heart to keep fueling you at running speed to a distance of 7km non-stop?

If you train, do you start from crawling, walking, skipping, jogging, running ?
So if you want to train your heart to keep going for 7km, how much exertion to ensure you can run non-stop? Do you use high-speed or pace ?

Keep in mind I do not know your age, fitness and health level. Do not exert yourself to death. Other readers please take care of your health first.

Breathing goes into lungs.
Heart pumps blood, oxygen and nutrient.
Muscle burns energy, but muscles cannot consume all the fuel.

Organs cannot stop so body needs to apportion for all bodily functions.
Even if you do not feel out of breath, does not mean your physiology is not tax out.

Maybe it could be muscles and mental strength.
There are suggestions from Vrese and Kidicarus you can try.

I suspect after 4 months, you build a habit for resting at 3-4km mark.
I caution you about your fitness and health level as above.
The method I first suggested enables you to train yourself.
Even when you are in advance level, and to break the habit by replacing rest with pace.

This far you have not feedback on any training techniques.

You keep on chopping trees and realize you are not getting more lumber.
If you do not take the time to sharpen your axe, then it will become more blunt.

It is not uncommon for people to lack the ability to train themselves.
So it make sense now suggest you may need to hire a trainer.
Tell the trainer what goal you want to achieve, or what training techniques you want the trainer to help you train.

Enjoy yourself.

life4 does not want to feed a dog LOL