Future is unpredictable but the present is in your hands and you have the complete authority on what you do :)
People have done it in the past, there are many success stories, where people cleared and even topped in competitive examinations, with self preparation. So, it is quite possible, you just need to work hard to do it.
You can arrange for all the study material through teachers & friends, and can manage your studies accordingly. Prepare as per the syllabus and keep attempting various practice and mock tests, to analyze yourself and be updated with the competitive environment. Tests are considered to be the best possible way for revision, as they test your complete syllabus in a limited span of time.
It's just that, times have changed and situations are not the same. GATE Exam is now conducted online and there are many online tools that need some time to adapt with these tools. So, along with the preparation, you need to practice some online test series, such that you adapt with online tools like Virtual Calculator & all, with time. There are many platforms offering free online test series, like : MadeEasy, EduRev, GateForum and all such platforms.
All the best for the preparation and you can offer me a treat, when you clear the exam with great marks :)