So I really like the gothic lolita style, and thought I would stick only to that. But now sweet lolita is starting to grow on me  so can I do both?

Of course!
You could wear all the lolitas if you like~

(and don't listen to anyone who tells you any different)

I went from goth to sweet. not over a day of course :) it's difficult to blend the styles but you can either create a black sweet look for starters or you can wear gothic/sweet ever second day :) I think that's how i got started. I still have one gothic dress that i never use, but i keep it anyway ^^ everything else i sold to finance my sweet wardrobe ^^ I guess money is the biggest issue since changing colors requires a completely new wardrobe. (at least in my case where i went from black to pastel). Time will tell if you'll like them both or change direction again :)

Lots of people combine multiple styles, and I´m not even referring to lolita specifically. You can like whatever you want. It´s not bad to like both of them and want to wear both gothic and sweet. There´s no rule that prohibits your wearing both styles.

Hahaha, your closet will definitely be interesting then.

Of course, it might be hard to wear them at the same time, but you definatly don't have to stick to one. start with buying one sweet coordinate and work with that for a wile experiment with colors and acsessories do you still want to wear dark colors, fine, If you want to incorperate pastel pink into a gothic wardorbe, that's cool too.