Hi,
I am fluent in estonian, french and also some finnish.
Compared to other languages, swedish can be relativly easy to learn. I use to speak some basic swedish several years ago, but i gave it up to focus on other things. From my point of view, european countries such as estonia, finland and sweden, as well as most scandenavian countries, have very similar languages. As you learn more, you will notice many similarities.
Learning other languages, although some disagree, is easier the more languages you already know. I found learning finnish to be quite easy as there is close to estonian. Languages like french have annoying grammer, however swedish does not follow this really. The only thing i suggest is you learn all of the accents you find in most european languages and how each language uses and pronounces it. it can completely change how the word sounds.
Since you are so dedicated, i advise you invest in a tutor or a good learning program. Do not use unreliable sources such as google translate or any other web translator as they are not accurate. Although they can reach some expensive amounts, possibly buying a program like rosetta stone could be worthwhile. My friend learns german off there, although im not sure how fluent she actually is since i dont talk much about it with her haha.
Immerse yourself in the culture of it. it makes it a lot more fun and interesting. I live in australia, but i constantly make estonian foods (im half estonian) and i recently revisited the country. If you can, maybe persuade to go to a country or place that speaks some. Even enroll in a saturday school.
A key point is constant practice. I am learning finnish because my best friend is from finland. Its a good idea to try find someone who already speaks it, as it helps you learn. We have finnish conversations and it helps so much. I am the only one in my family who still speaks regular estonian, so i often have conversations with people online from estonia, or just google estonian worksheets.
i really hope this helped. You can learn most basics within a few months if you really put your mind at it. i have been learning french for four years now and i am pretty much fluent in it, although i found french very hard. I went to french classes several times a week during school which helped. I would say maybe a year, give or take. Even when you are fluent, you still should remain studying it a bit, just so you dont forget. i have forgotten all the German i learnt for 1 year and the italian i learnt when i was younger (i was almost fluent in that)
Set yourself goals. maybe try learn all your numbers within a certain time period, then all your basics like i, me, my, his, her etc. Set an exercise each night such as reciting all your numbers, or writing a paragraph and complete something like this daily, just for challenges.
Learning more languages is really good for the future. It opens up so many job opportunities and the possibility to travel more. good luck with all your learning!