Gossip about my sexuality at work and the law that protects me

I am in my 30s and discreetly gay at work (although not "in the closet" as my social media is clearly telling everyone I am gay, although nobody at work knows me on social media). I recently revealed privately to another gay work colleague that I was gay (no I wasn't chatting him up lol). Now, however, the whole workplace - maybe 100+ people who see me on a daily basis - knows I am gay and many of them have changed the way they interact with me. Some of my work colleagues ignore me completely, some snigger at me as they walk past etc.. Although I am not ashamed to be gay, I am humiliated to be the subject of everyone's gossip, which means I am probably going to have to find another job just to save face. However, I am SO ANGRY about this whole situation that I want to try and use the law (in the UK, the Equality Act 2010) to salvage some dignity and teach the homophobes and gossip that there are repercussions to their behaviour. Do I have a serious case? And what is the procedure to begin this complaint in earnest?