Zac is correct. The past couple of years the whole drafting environment changed. As per advice it could be better to either get a technical qualification but that could also pose a problem. Few places give online/part time courses in Mechanical Engineering. A College is the most likely option but you can only go to N6. That said one can work toward obtaining a PRxxx certification at the Engineering Council.
Also as mentioned, drop hints that you can do free lance work.
Another thing one should do is get legal cad programs. It is not worth it to go the other route. Go and investigate this. I got a whole CAD suit from on supplier. It actually costs less than only two of their mainstream packages but you get a whole lot more programs.
I went my own way and are not looking back. Yes it takes time and you worry a lot but still worth it. Also the quality of worth you do is a big factor. Eventually your availability spreads by word of mouth.