Should I still be vomiting daily 4 years post lap band surgery?

No!  You should not be vomiting daily with your band, your band is too tight and you are at risk for a band slip, or may have already had a slip.  You need to have your band unfilled immediately, and if that doesn't relieve this issue, you need a band removal.  Once your band is unfilled, and you aren't struggling with food getting stuck, you may be a candidate for a revision to the gastric sleeve. 
Please don't wait to see your doctor, have your band unfilled under fluoroscopy so the doctor can evaluate you for a band slip, and then review your options.

Hello, thank you for sharing,
The best recommendation is to contact the doctor who perform the procedure, it's for your best if the doctor checks on you  and/or prescribe medication.
In addition to other criteria such as medical indications and safety, behavioral health assessments, and so forth I recommend that you go to your certified doctor so he can guide you and do the check up necessary to assist you.
My  Best Wishes