Dyscalculia: How Have I Never Heard Of This Before?

I was shocked yesterday to read about a numbers-related disorder called dyscalculia, similar to dyslexia but number-based. It described numbers-related troubles I've had for as long as I can remember. So I'm not just dumb/ too flighty to calculate things correctly? There might actually a problem with the way my brain deals with numbers and number concepts? How did I not know this existed?

I've developed ways to hide or get around when I can't process numbers the way I see others do. For example:

• I give my wrong # address or phone number, only to be asked, "Oh, did you just move?" when I have to correct it. No. I just get numbers wrong. I can't write down a string of numbers correctly being spoken to me. (Thank goodness for texting and email! Or I ask the person to write the numbers down for me.) I don't count change or numbers told to me, because I can't do it quickly enough. I just nod like I understand. I don't. 
• Friends calculate tips for me, because they've learned I can't do it quickly or accurately. If I do it myself, I just add a large number to the bill to make sure I don't under-tip. If I have time alone, I can do it, but it takes a while.  
• I get the times wrong when I have to tell time with a non-digital clock. I often don't calculate hours correctly; for example, sometime I think there are 10 hours between noon and midnight, and sometimes I think it's 14 hours. I can't remember by default it is 12. I have almost missed several flights because I got the time calculations wrong, until someone else pointed it out to me. (In China, their use of the 24 hour clock helped a bit.) I use a visual calendar to calculate days and weeks correctly. I can't do it in my head. 
• When I took the ACT my senior year, I scored a perfect score on the reading and English, but I was doing math on a 6th grade level, according to my score results. Red flag? Oh wait, I can read and write really well, so it doesn't matter. I was in a liberal arts track in high school, but failed required chem and math courses. I was allowed to do other things to make up those credits so I could graduate. Again, I could read and write really well, so it was overlooked.  I think it was more acceptable for me to skirt my way through school without being able to process numbers because I was a girl? 
• I shied away from buying a condo because I couldn't understand the financial calculations to process the paperwork. I'm still guilty of this. 
• I can't tell my left from my right without thinking about it, and this just mostly makes people laugh. Like, oh, that Rebecca, she's so flighty. I've come to believe this about myself, too, that I'm just too flighty to do the things other people can do so quickly. I got lost all the time as a child because I couldn't process directions given to me or find my way back the way I went. I'm good at reading maps because I have to be. I can't follow verbal or written directions without a picture map. 

Do you have these troubles too? Maybe there's help for us! It's nice to know that with some mind-training, there is a chance I can overcome this? A little late in life, perhaps, but never late that never.