You was learning English more than 20 years ago! I can't even imagine how it was difficult for you to study without Internet. I know you don`t like it, but it much easier to build your vocabulary by using online dictionaries instead of paper books. Just try to find something that works for you.
Abbreviations and Acronyms DictionaryNow, look at this picture:
You see Abbreviations and Acronyms Dictionary (Abbreviations.com), one of my favourite dictionary! As a freelancer, I work with articles which contain different acronyms and abbreviations, and I often rack my brains in order to make sense of some of them. It is impossible to know everything like the back of your hand, and that is why this dictionary is useful.
I'm not sure if it can be useful for you, but you definitely should try it.
Here you can find not only a definition, but also a list of synonyms, examples and - the main thing in this online dictionary - "mnemonics (memory aids) for ...". There are a lot of different mnemonic techniques that are useful, and thousands of language learners use them every day. What is more, they are ready to help you to memorise the unknown words. Of course, sometimes there is no logic in their explanations, but it works for them!
There are other ways you can use in order to build your vocabulary.
It always takes a lot of time to look unknown words up in the dictionary and memorise them. But if you want to make progress without spending much time, you can always sign up for some English course on this site. Other languages are also available!
You can use this site for improving your writing and speaking skills: www.synonym-finder.com
You must never forget about using synonims and antonyms, and "Synonim Finder" helps you to avoid repeating some word! It also provides every word with a definition and other information you may need.
These online tools are only the tip of the iceberg! There are a great number of different sites you should really visit! You can start from this one: https://quizlet.com/_3awd5o