Sometimes a person accused of harassment retaliates by further harassing or bullying the person who has lodged a complaint. Or in some instances an employer might treat a victim of sexual harassment unfairly because they are perceived as being 'difficult' or causing problems in a team.
This should not happen, and you have routes to redress against it. Your employer is not allowed to victimise you for complaining about sex discrimination or sexual harassment at work.
If you are victimised for complaining, or for helping a colleague to make a complaint about sexual harassment where you work, you can make a claim for unlawful victimisation to an employment tribunal.
If you have a union rep, you should let them know that this is happening at the earliest opportunity, and get their help in dealing with it.