Congratulations on finding a good job, which can be quite a struggle these days. Having majored in a science, you've undoubtedly studied statistics. With an IQ that is well more than 2 standard deviations to the right, you are highly intelligent. That can be a mixed blessing. Doing well on an IQ test tends to correlate with academic success. Unfortunately, there are a lot of good things that having a high IQ doesn't correlate with. Here is a link that takes a humorous look at the issue:
http://www.cracked.com/article_19174...elligence.html
It might be good for you to read up on the topic of the special difficulties faced by people with high IQs. Those include difficulties that start right off in childhood and can lay the groundwork for loneliness and unhappiness. Sounds like you know how to set a goal and get to it. So, besides having intelligence, you have discipline.
Having been able to target some goals very effectively can make it all the more frustrating to find yourself not making much progress toward other goals that you have, like establishing an emotionally satisfying relationship. Volunteering at the Humane Society is not going to be your thing. Luckily, you have lots of varied interests and you live in an area rich with outlets for those interests. Going to music shows and coffee houses provides high quality leisure that a hard working person in a demanding job, like yourself, needs. Finding a good relationship may take getting into an activity that is more focused than what you do for leisure.
You haven't been living in a cave all your life. You've been out there mingling. So you've already figured a lot out . . . like the wisdom of not getting totally hooked up with an recovering addict/alcoholic. You have a right to select the kind of person you want to get closer to and not just settle for who you bump into. That involves real hunting. It takes advanced interpersonal skills that don't get developed by all the studying, writing, and drawing in the world. Those skills and interests make life interesting for you, and they make you an interesting person. Relating successfully to people takes a whole other area of expertise. You must have some of it already, since you are able to hold down a job. Building on what you have can take a lot of very hard work and, even, some heart ache. The alternative is worse, though, IMO.