I'm not being funny here, but as the industry stands, that qualification is only worth whatever skills it gave you. Qualifications count for very little in the web development field. So many top designers/developers have no formal qualifications it's frightening, this is good cos anyone can do it without devoting a lot of time and money to formal education and it is bad because anyone can do it without devoting a lot of time and money to formal education.

In your situation, I'll simply echo the other replies - build a portfolio and develop your skills. Both are equally important. You can't prioritise one over the other. If you want it then take the plunge but be ready for the consequences. Go for web design full time or don't that's your call and depends on your circumstances but either way if you eventually want to make it work, you have to put full time effort in otherwise you won't succeed.

You have to make it happen. When you feel confident in your ability and think you are capable of delivering the right services to the right standard then I say go for it. No half measures. But bear in mind I'm talking absolute commitment here, not recklessness.

Oh and jacob's right when he says specialise, it's very important to pick a niche. Same with any field really, use the knowledge you have gained through your past work. How did you succeed? Those same principles apply it's just that the specifics are different.

Good luck.

Pete.