The best way to keep a long term relationship.?

hey guys, i need some advice on how to keep a long term relationship with my girlfriend. we have been going out for 8 months and we have had a few issues with each other lately and she is starting to lose the spark in our relationship. she loves me and i love her but i think she would like some space to herself, and because we mostly see each other all the time i think it creates arguments as we have nothing to talk about and bicker about absolute nothing. Is the best way to create the spark again, to let her have some space to breathe and see each other less often, i really do love my girlfriend, i know i sound sappy, but i really do, never met anyone like her, she is amazing. i really want this relationship to carry on working, i really would appreciate your help guys and girls out there. Thankyou :)