If you entered without inspection, you usually cannot adjust status inside the US, even if you’re married to a US citizen. Most people in this situation need consular processing and a waiver for unlawful presence.

The key issue is whether you qualify for a waiver. If leaving the US would cause extreme hardship to your US citizen spouse, you may be eligible for an I-601A provisional waiver before leaving the country.

This is not a simple case and small mistakes can have big consequences. Many people in your situation get approved, but only with proper legal guidance. You should speak with an experienced immigration attorney before filing anything.