If you don't speak any other language than English (your website says you're Scottish) there's some positives in that also as you will have a strong place in your brain for Finnish as that "other language" and you won't freeze so easily when you must speak it. What I'm trying to say is that I at least find myself very often "frozen" when having a conversation in a language in which my level is similar to another language. Polish and Spanish are both languages that I'm able to survive with but if I'm looking for the word e.g. for "Saturday" in Polish I might suddenly find myself stuck in the Spanish word for it. Add Swedish to the confusion and I might as well give up and hope to be understood in English, which is also not my first language, but at least I have a much more strong grasp of it than other languages (except Finnish) so that it isn't subject to the confusion most of the time. YMMV but I hope you get the point and maybe even find some encouragement in it to just start learning Finnish straight away.
Also, since you are Scottish you might already be able to roll your R's and pronounce the letters "ä" and "ö" the "Finnish way" since at least some Scottish accents have those "sounds", which is not the case for e.g. Australian, North American or Southern English accents.
Let me know if you want a Finn to talk to and I'll shoot you an email. ;)