"How do I tell my female friend I have really strong feelings for her?"
I've had strong feelings towards a female friend of mine for about six months. We get on well but every time I try to tell her how I feel, I get the shakes and end up changing the subject. I'm so scared that I will lose her to somebody else but don't want to be possessive in a friendship or relationship.
OK, let's get a few things straight first. If she liked you back, does she have the type of personality and confidence to let you know if she wanted more than friendship? If the answer is yes, this is how I'd play it.
Suggest, really lightheartedly, that you had a dream the night before about the two of you together. Watch carefully for her response: does she look a bit taken aback but sort of pleased? Or does she instantly come back with "Oh God, that would never happen, would it? We're just friends!". If it's the latter, you've got your answer and need to think about if you can be friends with someone who only wants friendship with you.
If she looks a little intrigued, say 'Have you ever thought about it?' and see what she says. If she says 'yes', that will give you the courage to spill how you feel.
If she's as shy as you are and you suspect she might feel the same way but is as nervous as you about taking it further, why not write her a letter or email? Tell her you have feelings for her but are too nervous to say them to her face, which is why you've written them down.
Say even if they're not reciprocated you would still like to be her friend (if, indeed, this is the case) but would hate for her to feel the same way and not know how you felt. Then, you will have to wait for her response. It will be agonizing but at least you will then know where you stand.
If she doesn't feel the same, lick your wounds in private and see her when you feel stronger. Tell her you're cool with how she feels and then continue the friendship as it was. It will feel a bit weird for the first few times but if you continue to behave normally, she will too.
You sound like a really nice guy and if she doesn't turn out to be the one, there will be other women who will love you. But better to have spoken up, than - as you said - lose her to someone and always be left wondering.