I’m a little confused on this matter. I have taken a mortgage out as we were paying rent which is a major waste of money if you have money for a house deposit because the rent keeps increasing along with house prices. Now I know in Islam eating riba is haram but at the same time taking the loan out is helping the person eat riba right?

It is permissible to take the money from the bank that is financed by non-Muslim government or private funds but not with the intention of loan. The knowledge that the bank will sooner or later force him to pay the capital as well as the interest does not affect [the lawfulness of] his taking the money.
Borrow money with the niyat of istenqadh. You can receive the money not with the intention of borrowing it. That is called istenqadh