How can i fix this?

We bought our van already converted so we have zero experience with building, much less a plumbing situation.

The first picture is what the plumbing setup looks like under our sink. The second picture is where the problem is at. The tubing that runs from the fresh water container to the sink has a permanent kink that's causing a problem with running water. This kink is because it has to be bended in order to be placed inside the container. After two years now of doing that, it's nearly not usable.

My question, can i just go to Home Depot and buy new tubing or should i consider a new setup? Is there tubing that's flexible so i don't have to replace it again in the future?