Since having Botox yesterday I’m having worsening pain and getting welts. I never had this reaction to Botox before.

What you describe is not typical. You should check with your injector.  It sounds like the pH of the injected solution might have been off.  Maybe you have developed some inflammation.  Go get checked out in person.  

So sorry to hear you’re having a difficult experience with BOTOX®. Without a picture, it’s impossible to say whether the bumps that have developed near your eyes appear to be normal side effects or a cause for concern. To be on the safe side, I would contact your provider and let them know what you’re going through. You may need an in-person visit to get to the bottom of what could be going wrong. Hoping for a smooth resolution for you.

Photographs would be extremely helpful, but without them I can only guess that you may have either a bruise or an allergic type reaction. If the area continues to swell I would consider going to an emergency room or at least visit your treating physician. Good luck from New York City

Honestly, it's hard to comment on your case without seeing a photo or evaluating you in person. I recommend you followup with your to discuss your concerns. Bruising and swelling are possible after any injectable treatment including Botox. The burning sensation during the injection may have been because your injector reconstituted the Botox using non-preserved saline rather then preserved saline.