I desperately need help with Simple Video Embedded

I could really use some help figuring out how to use Simple Video Embedded for self hosted videos. I would love to be able to use Viper plug-in but I am using the Gallery theme (a child theme of Thematic) and the video shows up in the description and not the artwork container to the left of the description.
I know that there are instructions for code that you need to include in your loop in order for you to be able to use self hosted videos with Simple Video Embedded, but I have had no success.
I have tried several times to write a function using the code that they suggests and inserting it in my existing code that I’ve had no luck. Here is a function I wrote:

function p75GetVideo() {
string p75GetVideo(int $post_id)
bool p75HasVideo(int $post_id)
}
if ( p75HasVideo($post->ID) ) {
    echo p75GetVideo($post->ID);
}

I’m not even sure the function is correct. If it’s not if someone can tell me what I am doing wrong I would greatly appreciate it. Also where do you insert it? I have been trying for a really long time now to figure out how to make this work and then be getting discouraged. Even if you could just point me in a direction I would greatly appreciate it. If you need more information (I’m not always sure what I need to provide), please ask I will provide you with as much as I possibly can. I don’t know if you need to see my website, but here is the link: https://www.stimadesigns.com/ctc/.
Thank you in advance!