I been with my girlfriend for 5 years we have a son together we had a row after the row to days later tell tell me that she has a talk with god and god tell her I am not her husband so she break up with me what should I do

What country?
You aren't her husband. Maybe God will tell you to ask her to marry you.

Are you on the birth certificate? All you can do (if not) is try to establish that you are the child's father by getting a DNA test, either with her consent, or by going to Family Court. If you are on the b.c. go to court to apply for shared custody.

We live in the bahamas I ask her to marry me and she said yes but now after the row she say god tell her I am not husband and never will be