The sentence you provided is almost grammatically correct, but there's a small error in "never ending." It should be hyphenated as "never-ending." So, the corrected version would be:
"It felt like a never-ending journey. I’m eternally grateful to God for the success of it."
**Meaning:**
The speaker is expressing that the journey (likely referring to a personal or professional experience) felt interminable or very long. Additionally, they are