Hi CamillaRose
You shouldn't convert to Islam just because you think it'd be fun or practical or interesting. You should convert to Islam when you are convinced it is true. If you are convinced it is true, but don't revert, then you'd just be fooling yourself, wouldn't you? And the other way around, if you're not (yet) convinced it's true, but already convert to go ahead and give it a try you wouldn't be really honest to yourself either now would you? I understand you are worried about how other people will react, I worried about that to when I was converting to Islam. However I bet that I don't need to tell you this because you already now that this is irrelevant. In the end what matters is that you do what you believe is right, right?
As for you second fear, I shouldn't worry about that to much. When a person reverts to Islam, all of his/her sins are erased and you start with a clean slate. And most Islamic communities are very open to reverts. In fact quite the opposite is true that sometimes Muslims start to think of reverts as "better muslims" (which of course isn't correct either).
Have you read (a translation of) the Qur'an? You might find that peace of mind you're looking for there.
You can find it online to, the three most accepted translation to English are:
Shakir
Yusuf ali
Pickthall
Here you can find all three next to each other verse by verse.
And here you can find tafsir ibn kathir, an in depth exegesis of the Qur'an.

May Allah the most glorious and high; guide you to the right path.