There is no going back
How many times do we find ourselves saying "if only I had known"! We would rather get it right the first time when we have to choose an option, so it is frustrating to discover that your decision doesn't live up to your expectation. For instance, we often invest money and time studying English in an conventional way, such as taking an expensive course, with poor outcomes. Why don't we usually take get so many advantages of benefits from that as we expect? I think one reason could be that we hope that just going to the study center let make us free to frees us from working hard. It is the same like as when you want to be get in shape and choose going to go to a gym center (<em>or</em> fitness center) rather than exercising at your own home everyday. Sooner or later we find out that there aren't shortcuts if we are going to succeed, therefore we must do our best. For instance, I have realised that my English have been has improved (<em>or</em> has been improving) steadily thanks to using Italki and I ask myself (<em>or</em> I challenge myself) to write an entry every other day. In the a nutshell, hard work pays off, so there is no going back and I am going to put have my heart set on writing on Italky despite having not enough as much free time as I would like.
Very good Angel. My corrections are in red and my suggestions to sound more natural are in blue/grey.
In your final sentence, there are two ways to say it:
despite having not enough free time as I would like
despite having not as much free time as I would like