Using an image sequence as a "bar" for my GUI?

I found some documentation on using image sequences, but I haven't found anything that makes sense to me.

I code in c#, what I don't understand is what is the basic code is to Load an Image Sequence, and how would I go "plus or minus" in the image sequence?

Example is, when you click it makes your player jump and the 'jump bar' decrease, if you collect a coin the 'jump bar' increases. i have an image sequence 00-49 images, so i just want the script to say if click decrease image seq and if collect coin increase.

Im not sure if that makes sense or not, but anything would help!