oracle – Insert query in Orcale database – not showing the row in a table

I am inserting a row in the Oracle database table. The query looks like as below –

INSERT INTO <schema_name>.<Table_name> (SID, LABEL, DESCR, GTI_EXPTYP, GTI_MODUS, GTI_NAME) VALUES (22, '21.01.2019, 08:10:10', 'PDJHF q_sz_nlp (Update)', null, null, null);

I have executed the above query 3/4 days before. And the result of the query execution was –

1 row created.

But I do not see the newly added entry in the table. I thought, I need to commit. And now, when I am trying to execute the same query again and to commit, the query execution is not proceeding (stucks/hangs the terminal). Could someone please help me to understand what is the issue here?

I am new to database handling. I am using sqlplus tool.

Thanks in advance!!