How do I make space on my phone, if everything keeps giving me an error message?

[AC Question]

So, recently my phone has been running low on space.
I also have this messaging app called "Kik", and it tends to eat a lot of my phone's memory.

It grows from 15MB to 290MB in an hour or 2, with the reason being the fact that I'm in a group chat with 25 people who are pretty active. I think Kik saves every media sent in the chat to my phone.

And I can't prevent that from happening.
However, it's not only Kik.
It's also WhatsApp, Google+, and Instagram.
But I don't have to worry about those, because I can simply delete the Cache.

I think my phone has 0.00B left, because I can't open everything.
Because everything keeps giving me an error message like "[App ID] has stopped working".

I have a lot of photos and videos saved on my phone, I keep forgetting to transfer them to my micro SD card.

My PC is pretty bad too, because it detect any USB device unless it wants to.
The only USB device it accepts happens to be my USB flash drive and nothing else.

Is there any way besides formatting my phone to fix this?
My phone is a Samsung Galaxy Trend Lite GT-S7390

 

[Golfdriver97]

Welcome to the forums. The limit is the fact that there is only 4 GB of internal storage on the device. That leaves the user with maybe 1 GB for use. And that's a large maybe. I would transfer the photos to your card now, and move them to your PC. That is probably the only way you can gain more space.

 

[JustXavier]

I know that I'm only able to use 2 GB, but I can't open ANYTHING.
When I go to "My Files", it stops working.
When I open up my settings, it stops working.
I really can't do anything on my phone.
Even TouchhWiz stops working, I can't access anything.
They just stop working, and like I said in the description of the question.
My PC doesn't like USB Devices or anything USB related, I really can't do anything at the moment.

 

[Golfdriver97]

You may need to consider a factory reset. Can you access any settings?