Had Migraine. Vomited. On Aspirin, Lexapro, Lorazepam. Ativan Shot. Now Feel Numb There. Pain Is Increasing. Suggestions?

Hello,

About 2 months ago I was in the ER for my first severe migraine (my mom has always had them and once I was vomiting every 10 minutes I knew that I needed to be seen). I explained that I was unable to keep anything down, including any medicines that I normally take (aspirin, 10mg daily lexapro, and .25mg lorazepam once nightly) Once I was seen, they gave me some IV fluids and nausea medicine which fixed up the migraine issues, I was also given a shot of ativan in what was supposed to be my left buttocks muscle. The nurse was very abrupt and I believe she rushed the shot because since then I have had increased pain and numbness in my left butt, hip, and thigh. There was a small bruise for about a week afterwards, and since then I have had increased numbness and pain in the areas previously listed. I feel it most when I do any physical activity (walking, running, even sitting down sometimes) or when any pressure is put on my left butt, hip, and thigh. When I press my hand into the area, it feels very strange, I feel pain and mostly complete numbness. It has only increased with time and I am worried that there has been nerve damage. Could this be serious, why is the pain getting worse, and what should I do? I am concerned that it will continue to get worse and have not looked into it until now because I thought that it would go away with time. The pain is starting to increase to the point where I have to sit down and lean only on my right side, otherwise I feel pain and numbness that feels like my leg will give out.