Can anyone give advice on changing careers or starting a career in interior decoration? Anyone who has experience in this field or had experienced it.

Let me begin by saying that I'm in my mid-20s and have an undergraduate degree in business with a major in accounting. Having practiced for 5 years in the field of financial audits and have obtained my professional qualifications in accounting whilst working full time. I'm on the verge of attaining a managerial position and whilst the pay is pretty good, the hours are treating me horrible and it is disgusting how political it can become. This has made me become disillusioned with the corporate sector.

Basically my questions are
1) how can you get started? I have the passion for it but have no structure in starting one or entering into it. I know how I can enter my line of field but this career path is beyond me.
2) I know that interior design and architecture is beyond me at this point. I understand that this is where the money is to be made, especially if you are the head architect. But what I also understand is that a) it takes 3 years to get a diploma and then another 3 for a masters before you can practice, b) the architect and interior designers focus at the structural side of the building and only about 10% of their time is spent on interior finishing, colours and textures. I'm more interested in the interior finishing. Is there a part time course to learn the basics of interior finishing and CAD that certifies me?
3) what defines a good and successful interior decorator from a bad one? I'm speaking about both financial success and of course delivering value to customers.
4) what are the tough parts of the job? The not very nice things about the job? The ugly of the job?
5) in my country, the term interior design and interior decorators are used interchangeable (and more understand the term interior design). But what many don't know is the difference. I'm wondering how do people differentiate themselves and build a large client pool to be successful when you don't have much experience to show off your portfolio?
6) any other advice?

What I don't need to know is stuff like "you need to suck up to client's demands and be under constant pressure to deliver". This is the same with all jobs and my current job. Whether you sell a product or a service to a client (a human being) we all act with rationale and would demand what we felt was up to the level of quality to commensurate the money we depart with.

Thanks and I look forward to reading your responses