I started my in-home personal training business in March 2006 and it's been doing pretty well so far. You obviously have to get your name out there and find your own clients which is tough but it gets easier after you've built up a clientele and reputation. I've been certified by the ISSA as a Certified Fitness Trainer and Specialist in Performance Nutrition for almost 7 years now. They aren't the best certifications but they served me well and will get you a job at pretty much 98% of gyms and health clubs. Last year I got my NSCA CSCS and CPT certification which are obviously superior and they are accepted absolutely everywhere. I would say the CSCS is the gold standard since only college graduates can get it.
If you are looking to be a college or semi-pro strength and conditioning coach, you obviously need the CSCS. There are tons of colleges in the area, I'm sure you could find a job somewhere if that is what you wanted to focus on. Pay is pretty bad from what I hear as a strength coach, and the hours can be extremely long. You reeaaally have to love what you do and love training athletes.
If you want to be a personal trainer, you technically don't need any certifications! I would say less than half of the trainers out there have an active certification. You are already ahead of the game having a college degree in exercise physiology or health science, i forget what you finished with. Having certifications makes you more marketable and may help you get a job quicker but it isn't a necessity at a lot of gyms and health clubs. I would still recommend getting your CSCS to cover all your bases and make you a stronger candidate.
I started out working at YMCA's when I was 17 and did floor hours, new member orientations, cleaning, free training sessions, and substituted for other trainers that went on vacation. If worst came to worst, you could always get a lot of hours or a full time job at the YMCA. There are plenty of old and lazy people at Y's and you might even be given some clients right off the bat.
Don't get hung up on certifications, send out the applications/resumes, practice training friends/family/neighbors, and get some work experience in for cash, at least part time. Learn as much as you can about fitness and nutrition.