“Invisible Children,” a documentary filmed by three American college students, Jason Russell, Bobby Bailey, and Laren Pole, who set out for Africa in search for a story; however, they discovered the immense suffering of a civilian population in northern Uganda.

For more than twenty years conflict between government forces and rebel group known as the Lord Resistance Army (LRA), has disrupted life for civilians in northern Uganda. Since 1986, the Lord Resistance Army has abducted, as many as, 20,000 boys and girls, once abducted, children are forced to commit and endure horrendous atrocities against civilians and other children. They are forced to become child soldiers and sex slaves, and must kill civilians and kidnap other children in order to stay alive. Children are turned into ruthless killers without feelings, they become numb by the atrocities they have seen and in which some are forced to participate. The constant fear of abduction has forced many children to flee their homes over night in order to avoid abduction from the LRA, children as young as five years old walk miles every day into urban areas seeking refuge, they find safety at churches, hospitals and bus stations.
Still, Uganda is in a desperate state of emergency, the conflict between the government and the LRA has resulted with the dislocation of more than 800,000 individuals. Many of which have fled to displacement camps. Within a three month period, 640 civilians were killed, and 2000 individuals had been abducted. Not only thus this demonstrates an affected Uganda, but is also uncovers the immense failure of the Ugandan government.

In the last sentence, should I say "the gorvernment of Uganda, or leave it as is?
Also, should I put a comma after "Not only in the last paragraph?

Thanks!

“Invisible Children,” a documentary filmed by three American college students, Jason Russell, Bobby Bailey, and Laren Pole, who set out for Africa in search for a story; however, they discovered the immense suffering of a civilian population in northern Uganda.

this is a huge run-on sentence. You need to put a verb in the first half and separate it into two sentences

For more than twenty years conflict between government forces and rebel group known as the Lord Resistance Army (LRA), has disrupted life for civilians in northern Uganda.
put a comma after years and get rid of the comma after (LRA)

Since 1986, the Lord Resistance Army has abducted, as many as, 20,000 boys and girls, once abducted, children are forced to commit and endure horrendous atrocities against civilians and other children.
Remove the commas after abducted and as. Put a period after girls.

Children are turned into ruthless killers without feelings, they become numb by the atrocities they have seen and in which some are forced to participate.
put a semi-colon after feelings instead of a comma

The constant fear of abduction has forced many children to flee their homes over night in order to avoid abduction from the LRA, children as young as five years old walk miles every day into urban areas seeking refuge, they find safety at churches, hospitals and bus stations.
This again is a huge run-on sentence... you need to separate it into 3 different ideas.

Still, Uganda is in a desperate state of emergency, the conflict between the government and the LRA has resulted with the dislocation of more than 800,000 individuals.

Put "still" after Uganda. Use a semi-colon instead of a comma after emergency. <b/>

Many of which have fled to displacement camps. Within a three month period, 640 civilians were killed, and 2000 individuals had been abducted. Not only thus this demonstrates an affected Uganda, but is also uncovers the immense failure of the Ugandan government.

Delete "of which". Delete comma after killed. Last sentence - These numbers not only show a badly affected Uganda, but also uncover the immense failure of the Ugandan government.

In the last sentence, if you want to refer specifically to the government of Uganda, it would be more accurate to say "the government of Uganda." However, if you are referring to the Ugandan government in a general sense, you can leave it as "the Ugandan government."

As for the comma after "Not only" in the last paragraph, it is not necessary in this context. The phrase "Not only" is functioning as an introductory phrase to introduce the following statement, so a comma is not required.