Hi and welcome to the forum.
I'll answer your points one by one as best I can.
Yes, nystagmus does increase when we're stressed or tired -- that's now well documented, so you're not alone there. Obviously it does make meeting people more challenging, but being aware of the problem does usually help.
People with nystagmus do an amazing variety of jobs. The list I have includes software developers, teachers, bankers, researchers, musicians, pharmacists, doctors, lecturers, mechanics, journalists, shop assistants, ticket inspectors, bar-staff, actors, waiters and waitresses, chefs, hospital porters, security guards, therapists and many more.
Yes, you're right that it's often harder for us to find and retain jobs than people with normal vision. But if you persevere and stay positive, you will find something. As you gain more skills and experience and become more valuable to employers, the fact that you have nystagmus often becomes largely irrelevant. Good employers will be flexible. Remember too that almost everyone at some point in their life has some kind of health or other problem which makes them less than "perfect" in employment terms.
As for friends and eye contact that can be difficult. But most people find ways of overcoming it. Hopefully you will get some suggestions here. I've always found it helps to be open about nystagmus and put people at ease about the condition. Most are interested and understanding -- although only tell them as much as they want to know.
Like many people with nystagmus I don't drive. I knew that from an early age, so I've always built my life around not having a car. That means living somewhere with good public transport and where I can walk to most places I need. Yes, sometimes, we do rely on others for a lift. So I make sure I show my gratitude and find things I can do for them in return.
No-one's suggesting that living with nystagmus is easy, but it's not the end of the world either. Try to find others near you with the condition - at 1 in 1,000 we are here. Talk to them and share the problems.
Hope this helps.