Rebecca.. check out anything by Capercaillie.....they do a lot of upbeat stuff.. but Karen Mathison has a beautiful voice and sings a lot of Scottish love songs and ballads... many in Scots gaelic...
if you like Irish.. I reckon you'll like Scottish.. there isn't an awful lot of difference (I expect others will disagree), apart from instrumentation..... more accordions and bagpipes for Scottish.. and the variety of tune types.....
if you want a fantastic Scottish song writer with any amount of love songs and ballads.. check out Andy M. Stewart....
slainte
alison