Yes you can obviously do self studies for any subject in CA and that includes SFM as well. And regarding the number of days it'll take to complete the whole syllabus of SFM will totally depend on your efforts and hardwork. But considering the amount of time left for your attempt, it can be safely said that you do have sufficient time. However, please note that you will be required to put in a lot of efforts if you want to clear CA Final exams. And here are the two study tips which will definitely help you (based on my personal experience).
1. Firstly, you need to prepare a time table for your preparation. I would suggest you to set a weekly target and then again break them into daily targets for your studies. Keeping targets will help you to motivate yourself to study harder in order to reach your targets. Otherwise, you will have no idea where your path is heading towards and you'll end up messing it up. And also it is important that take your targets extremely seriously. Every day you need to go after your target topics for that particular day as if your whole depends on it.
2. You need to be disciplined if you want to achieve anything worthwhile in your life. I'd say without discipline, it's literally impossible to become a CA. When I say discipline, I mean your self control. Many times, we prepare a time table for our studies; but for some reason we end up not following it. So what I want you to do is to strictly stick to your scheduled study plan (as mentioned above in point 1) regardless of whether you are ready for it or not and whether you like it or not. For this you need to keep all the distractions away from you while you're studying. And when you get tired and frustrated with your studies, just remember that you need to study only until the exams are over i.e., NOT FOREVER. So just sacrifice all the worldly pleasures for the time being so that you can have a wonderful future ahead.
If you follow these two tips, I can almost guarantee you that you'll be successful in your exams. Good luck :)