I dont understand the issue....at all.
1) As said previously, it is very unusual for two hetero people of opposite sex to be long term friends. For real.
2) You spend all your time with her, apparently she even gets aggressive and angry with you?
3) you make a thread and say you arent interested in more really, but you constantly refer to the friendzone issue. I think you arent doubting, you're in denial.
So how do we fix this, you ask?
1) make a decision. More with her, or less if at all. I.E. relationship or hang out sparingly.
2) execute decision. If more, then make a move or tell her you want to hang out, but on a date. Dont make it weird, just make your intentions known. If you decide not to, start returning calls and text slower, hanging out less and less. You obviously will never be emotionally available while friends with her.
3) If it works you have a new girlfriend or lost emotionally stunting baggage.
If you're posting about this, its an issue that needs to be resolved. Dont kid yourself, this only goes one of two ways.