This has to be really hard for you to have unnecessary worry. Some might say irrational. The reason it is irrational is that there are very specific ways someone gets HIV. If you know those, you can then easily see that your fear is unwarranted.
How does someone get HIV? They have unprotected vaginal or anal intercourse (with penetration) or share IV drug needles. Air and saliva inactivate the virus.
So, there is no way eating a burger could post an issue of acquiring HIV. I wouldn't be happy about a pubic hair in my food because that's nasty but it's NOT going to give you HIV.
You need no test. Lymph nodes reacting is part of your immune response. Being coughed on can cause you to have this reaction. And when mike_no sys the side of your neck to be sore due to stress, he may be talking about muscle tension. If you are overly anxious, that can happen.
So, you've now been educated in HIV. Wear a condom and don't shoot up drugs and you will never have to worry about HIV.
Burger and penis has vast differences. You can't and shouldn't use a burger to procreate!
HIV can't survive outside of body, in adults, HIV can be only transmitted through unprotected vaginal or anal intercourse or sharing needles intravenously with people who inject drugs.
Your post reflects that you suffer from an anxiety disorder and it warrants a professional's attention. You must evaluate your options to find out a good psychologist in your area where you reside to help you overcome such irrational though process.
You were never at a risk.