Your best option at this time is to make an advanced payment of the 45K. This will give you an appropriate period to buld up a further nestegg and you won't get a better rate on the funds. I would tend to factor out "debt forgiveness" in any strategy as it's highly unlikely to happen in a scenario that would benefit anyone who is still in receipt of income. Check with your mortgage provider first to see whether you have the option of making an advanced payment. Should not be a problem. By doing things this way rather than paying the 45K as a permanent reduction it leaves your options open should your financial position change.
I think 44 was referring to being able to get the €45k back without conditions. I dont think you will get that. However what you could do is reduce the term (same payments roughly) or keep the term and reduce the payments. As you are on SVR doubt that you will get forgiveness. You can always try.