Below is the list of documents needed for H1B Stamping:

1. Employement verification letter

2. Original 797 A

3. Attested I-129 copy

4. Copy of LCA

5. Bank Statement (3-6 months)

6. Pay slips (latest 3-4 slips)

7. All I-20s (including CPT and OPT)

8. OPT card 

And kick out the nervousness and welcome the confidence. You will be fine.