Annie, I know exactly what you are going through because I have been there myself.
First, be careful what you do to your "production" moodle. Make sure it is backed up. I think that Usman is saying that the change to Barracuda is not really required up to version 3.1.5. Maybe so, but I am not sure. I am running 3.2+ (Build 20161222) on my experimental hosted server, and even though it suggests Barracuda, it works. (Usman, at what version of moodle is this switch to barracuda really required? Are you sure it is at 3.1.5+?)
Many companies where you host your website offer a variety of "bigger" products. Many start with small "hosted servers," which is what it appears you have. But when someone outgrows their hosted server, you can step up to bigger servers. One step is to a Virtual Private Server, or VPS. When one makes this step, it often involves: 1) more money (i.e., costs more), 2) more knowledge, 3) a faster and more powerful server, and 4) a more flexible server. This is what I have for my own Moodle.
With a VPS, with #4, you can implement barracuda. But it requires #2. Often, people want to avoid #2, or #1, so you cannot upgrade to barracuda.
I am not sure which server companies will give you barracuda on their hosted servers, so you will have to check around.