If you really, really want to be a writer, there's one thing to realize: you can't wait for inspiration to strike. Think of it like lightening--a near miss is probably preferable to a direct hit.
Anyway, if you want to be a writer, you really can't wait. You need to start writing, now. And you need to keep on writing. And journals are not writing, so forget that. You can't count journals. You have to write every day on a manuscript or short story or something like that. I, personally, think writing every day may be a little excessive--you do need a day or two off each week. That's why they give you two days off each week from other kinds of work. But, you do need to write at least five days a week, preferably on a schedule, and not just that blog or journal junk.
Because the thing is, if you write when the mood hits you, you'll probably do it so sporadically that it will take you ten years to finish one manuscript and editors/agents are going to want to see a little better production out of you.
So set aside a specific time, even if it's just 15 minutes during lunch, 15 minutes before work, and 15 minutes after work. For me, I write between the hours of 8-10pm weekdays and occassionally on weekends. Obviously, I've had to give up prime time television, but hey, that's okay. Everything in life involves tradeoffs. I prefer to be a total ignoramus when it comes to popular culture, than to not write--or write only sporadically. It's either write at night or write in the morning and go to bed early, so either way, I'm not watching television.
Also--get busy. The busier you are, the more you will produce. Set deadlines. Get stressed out. These things are good. You see, the thing is, the more relaxed you are, the less likely you are to bother to write. It seems counter-intuitive, but being busy, knowing you are busy and have to keep to a schedule, will make you actually write more when you do write.
I also have a group which sets weekly, monthly and yearly goals, and we report on whether we've met our goals. The group therefore offers a way to "hold your feet to the fire" as well as offering support and encouragement when you need it. I really, really encourage you to either join a group like this, or create one. Lots of places (e.g. Google, Yahoo, MySpace, etc) offer free group services to let you set up a group, so look into it. It's worth it.
Finally, every year I do NaNoWriMo. That is National Novel Writing Month (http://www.nanowrimo.org) that challenges writers to write 50,000 words during the month of November. Do it. You will amaze yourself and others. :-) You will learn what you really can do when you drink too much coffee, set unrealistic goals, and don't shower for a few days.
You really can write 50,000 words in 30 days. Really. And after a few days, you sort of don't notice the stink anymore.
Now go and do it.