Do you have another friend you can trust to talk to? It's never good to deal with someone who is always belittling your problems. Yes, maybe hers are worse, but hers are nothing compared to the AIDS problem in Africa. Just think of it like that, you don't HAVE to put in perspective because there will always be someone worse. You are still entitled to your feelings and your feelings are legitimate and deserve attention.

I'm not saying you should just dump the relationship, but maybe you can start forming stronger bonds with other friends you have and find someone who will be there to listen and help when you need it.