I think whenever you meet sentences that you think are complex, you should break them down into the most basic parts and try to understand the sentence as you piece it together.
to be desired for
As you said, this is the passive of 求める. If someone is 求められる, then they are being yearned for.
as if (I) was being yearned for.
ように is being modified by the clause before it. 求められる modifies よう here.
kissing as if (I) was being yearned for.
ように modifies キスする. How is he/she kissing? As if they are being yearned for. Obviously, with the lack of context, I cannot give you a very good translation because I do not know who is doing the kissing, but here is the gist of it:
literal translation: (We) kissed multiple times as if (I) was being yearned for.
natural translation: We kissed again and again, as if (he/she) wanted (me).