Hell is real. It's as real as the computer screen you're looking at. It is a place of unimaginable torment. There is no escape. It is the final and unending judgment of God  upon every unrepentant  person who has sinned against Him. And everyone has sinned against God.

"For all have sinned and fall short of the glory of God,"  Romans 3:23

To 'fall short' of the glory of God means to be less than He requires, which is to be perfect. Because all human beings are imperfect by nature, all have sinned against God.  Sin is anything that is unacceptable to God, whether it is something that seems harmless, like an unloving thought toward someone or something horrible, like terrorism or murder.

God is completely just to condemn people to hell for any and all offences. They will suffer the punishment that their crime deserves. Since they have sinned against an infinite God the penalty must be infinite and unending.

 "And these will go away into eternal punishment, but the righteous into eternal life."  Matthew 25:46

And these will pay the penalty of eternal destruction, away from the presence of the Lord and from the glory of His power, 2 Thessalonians 1:9

These two verses are describing people who have rejected Jesus Christ as  being the only one who can deliver them from this punishment. By not choosing Jesus, a person is necessarily choosing to accept the punishment of hell. There is no third choice.  And it is only in this life, here and now, that a person has the opportunity to choose.

And inasmuch as it is appointed for men to die once and after this comes judgment, Hebrews 9:27

After physical death, the punishment begins immediately and there is no appeal. There is no way out. God has rendered judgment, according to your choice,  and it shall stand, forever.

The good news is that right now you still have the chance to choose eternal life in heaven.  God loves you more than you can imagine and wants you to make this choice. He does not want anyone to go to hell.

The Lord is not slow in keeping his promise, as some understand slowness. He is patient with you, not wanting anyone to perish, but everyone to come to repentance. 2 Peter 3:9

God is giving you every opportunity that he can for you to choose Him and be saved from the terrible punishment of hell. Don't wait. Death can happen at any moment and then your chance to choose will be gone forever.