I agree that your needs need to be met here as well. There is nothing wrong with switching on occasion if, for example, you prefer to be spanked for a change. So, one day you are in charge, the other he is.
Your first step, however, has to be communication. You need to talk about both your wants and needs. This may involve you writing down and sharing your fantasies with each other (sometimes writing them down is easier than saying them out loud) and making a promise to each other to carry out at least one fantasy from each other's list at least once a fortnight (so one week it is his week to be dominated, next it is your turn to have something you like).
You may even go so far as to complete a BDSM checklist with him - looking at BDSM activities which you like to do or will not like to do. You can do this from both points of view - you complete it as a sub and as a Dom/me. This will give you an idea of what you both enjoy.
True BDSM is about the power and control you have over someone and while M/f BDSM is often about protection and care for the female sub, F/m is more often about the Domme having something the sub wants (usually sex) and controlling them through the application of that. Now, he wants kinky stuff so you can use that to control him. Get your pleasure first (often the case in F/m relationships - Domme cums first, sub second if at all...), make him do things in exchange for his pleasure - clean the house, do DIY, do jobs you hate to do yourself.
Finally... the pain thing... it is tough. I know from personal experience how tough it can be to hurt someone you love, even though they are enjoying it. I used to get really nervous about spanking because I was scared I was spanking too hard and that usually meant she was not enjoying it because it was not hard enough (pun unintentional there but left in because it fitsAnd there's another pun right there... I'll stop now...). In time you will learn to overcome that and be able to enjoy hurting him as much as he enjoys being hurt. One thing I might suggest - aftercare. Talking about it and hugging etc after a kinky act can help and make you feel more comfortable with it. Ask him if you hurt him too much, if he'd like you to hit harder or softer and so on.