it sounds like, and as others have suggested, you need to practice your conversational english.
have you thought about joining a local hackspace to meet up and socialise (google hackspace redwood city)? That or volunteer on local community projects. Both provide great opportunities for talking and practicing to battle your shyness.
From somebody who is themselves incredibly shy and adverse to social situations, sometimes the best way to get past that is expose yourself to stuff which puts you out of your comfort zone.
In regards to meeting women, I wouldn't worry too much about that. It will happen by putting yourself in social situations as a result of spending time with others and meeting new people. and remember, for every awkward guy out there without a car there's an awkward girl out there who wont mind.
So, to summarise. Get some hobbies that allow you to be sociable, volunteer with charities, join hackerspaces, go to talks and sociable events. Tell people whom you meet that you want to practice your English, they'll be more accommodating then you'd first imagine. Don't sweat it on meeting someone either, that will happen.
One last thing, from your post, it seems you sometimes feel depressed? If so, then go and speak to someone about it. Feeling isolated and alone can make us feel pretty ill. We shouldn't have to be like that.
Lots of people go through this, whether the barrier is language, extreme shyness or something else, but it's important to know it's possible for things to be different. Just don't get too anxious, and look after yourself and stay conscious of your wellbeing.