I can relate to most of what you wrote. I've always been chosen last in school as well despite the fact that I got a B consistently over the years. I was even told I was good at soccer for an amateur. I always tried my best. A few of the mean popular girls were always the team leaders and since a few of their friends hated me, they ended up hating me too although I never did anything bad to them or said anything bad about them.

I was a lot shier back then. I rarely stuck up for myself most of the time. As for you, it sounds like you might have anxiety issues. Maybe people aren't trying to ignore you. If you don't speak up, then the extroverts and more confident people will definitely not give you a chance at all. Especially in a competitive place like work.

Can you try to write down what you want to say and then speak up more? I'd speak to a therapist about this issue. It might help you deal with these issues. Maybe people overlook you since you don't speak up and maybe they think that you want to be left alone or assume that you don't have anything to say if you remain quiet.

Not many people will ask for your opinions during a meeting if you don't speak up. Even in a small one on one group the loudest and most extroverted person always dominates the conversation. That is why I hate being in groups. I will never ever introduce my friends to each other now because of this. I like my one on one encounters.

Anyways, I have similar issues with people. Is there anything that you can think of that you might be doing to repel others? Can you ask trusted friends for their honest opinions? If you're on good terms with your boss, ask him or her for their feedback on what areas you can make improvements on aside from needing to speak up more.

Look up assertive communication skills. Try to be more assertive outside of work too. Practice talking to store clerks. Do you have any annoying habits that you don't think is a big deal but that would be something that annoys other people? One former friend of mine didn't respect boundaries. She'd always interrupt me, talk over me, repeat herself, gossip a lot, try to control me, etc...

Is your hygine OK? Do you look at other people in the eye or not? Do you stare at them or stand to close to them? Do you talk to much or ask questions that are to personal or inappropriate? Did your former friends ever tell you why they stopped talking to you? If you see a pattern there, then try to change whatever those problems are.

If they complained that you talk to much or complain to much, then maybe that's something you need to work on. I'm just giving examples here. I've been told I can take things to personally at times. Maybe you might be a sensitive person too, but that's OK. Some people do have a hard time dealing with sensitive people though.

Try to ignore the people who are repulsed by you. It's possible they're just not nice people. It could be them and not you. Try talking more to whoever seems nice at work. Ask how they're doing, bring donuts to work. Put out a candy dish by your desk to attract people. Be a good listener as everyone likes people who listens to them.