ejtx, sweetie, I wouldn’t worry too much about the “I’m 25 and everyone my age has been going out and having fun for years and I’m missing out” part. Heck, I was barely out of college at age 25 (enrolled at age 21! :o ), and I practically never socialized with my peers until grad school. Maybe you’re just a late bloomer; you’ve got at least another 25 years before you get too old to party. 
It sounds like you may still have a bit of a problem with social anxiety. If you can find a congenial cognitive-behavioral therapist or group therapy program that your insurance will cover, some people find those treatments very helpful. If insurance won’t cover it, you might look to see if there is a free support group in your area.
If you feel you aren’t really relating to people you meet through casual social encounters, try putting yourself into situations where you can meet people who share your interests. This is where the “be yourself” advice comes in; it’s not that everyone is perfect just the way they are and should never try to change anything, but that you should emphasize the aspects of yourself and your interests and activities that are important to you, not the things that you think other people think you should think are important.
Think about the things that you really enjoy, and would enjoy doing, or talking about, with other people (RPGs? chess? tennis? bird-watching?), and look for nearby interest groups, clubs, or meetings on those topics. Then go to them (this is an important step 
), and talk to people you meet there. Don’t expect this to lead to lifelong friendships and earth-shattering romance right off the bat; just use it as an excuse to meet people and spend time doing stuff that makes you happy. If there isn’t anything that you really enjoy doing, you may be depressed. Talk to your doctor; it’s nothing to be ashamed of, it really does hurt you, and drugs / therapy / both will help in the majority of cases (about 1 out of 3 Americans will seek treatment for a psychological issue at some point in their lives, including myself, so you’re in good company). Social anxiety and depression are often related, as they each tend to cause the other.
Don’t hold yourself up to what you think other people are doing or how much fun you think other people are having; the vast majority of us are just struggling along being insecure too. The guys who live the Playboy lifestyle are mostly to be found in the pages of Playboy and other media that make money by making people think they aren’t seeing their fair share of life. Likewise, the all-consuming death-defying romances tend to come along a lot less frequently than Hollywood and Harlequin would have us believe. 
Your posts don’t sound robotic to me, just insecure and maybe shy. Everyone is insecure and shy at least some of the time, and a lot of us are insecure and / or shy a lot of the time. It’s not going to destroy your life unless you let it. The best advice you’ll get here is to figure out what will make you happy and go take your best shot at doing that, whatever it is.