Yes, you must amend to include your share of the 1099-INT income, since it is a joint account.
"Since my husband does not work" is not a reason for filing a separate return. In fact, it's a very strong reason for filing a joint return. You get to double your standard deduction and pay tax at a lower tax rate. And that's just the fundamentals.
Since you'll be amending anyway, you can amend to a Married Filing Jointly (MFJ) return.
