Keats

I am new to being poly and need some advice on how to stick with my personal boundaries in the heat of the moment. I am used to the traditional paradigm that women are taught which is that submissiveness is sexy and that using condom is always negotiable. I find it difficult to stick to my guns about protection, and I also have trouble with taking charge as to how far things go. Sometime I just want to make out with someone or maybe 2nd or 3rd base. It is hard admitting this but I just get overpowered. I am horny and let the other person push me. Instead of a fulfilling mutual pleasure inducing experience I am always left with a bitterness afterwards because I know I let myself down by not sticking to my intentions and values. How can I regain my power as a poly-woman? How can I communicate more effectively what my needs are? Any advice would be much appreciated!