Hello. I started learning another language alone as well (Portuguese). I bought 2 books (Practice Makes Perfect, and Living Language) and have been reading, doing the activities, and listening to the CD that comes with it. I also have a Flashcard App on my phone so I study vocabularies and verbs, etc. whenever I am on the train or car. I also stick notes on objects to remind myself what they are in Portuguese. At the end of the day, actually hearing the language is the most important. Once you know the basics, I think you should speak with others because hearing the language in your head is not the same as actually hearing it from a native speaker. Good luck!!!!!

If you don't mind my saying so, learning English alone is likely to be so extremely boring that it is unlikely you will be successful. To succeed alone, you will need to have a very strong motivation (such as your job requiring you to learn English to keep your job) or you will need to be extremely mentally disciplined (as very few of us are). If you could at least join or establish an English study group, the social interactions in learning a new language would make it immensely more interesting. May I ask why you wish to learn English alone? For example, if you could afford one or two English lessons a week, it could make learning English more productive (faster progress) and more fun.