OP, you need legal advice, and quickly.
I’m an employment lawyer.
Whilst there may be a potential CD claim here, the claim will fail unless it meets the fundamental components required - your employer must have committed a fundamental breach of contract, and you must accept that breach by resigning WITHOUT DELAY. If you continue to work there, they can argue that you’ve waived the breach of contract, or that the real reason you resigned was because you had a new job. That will make your legal position very difficult as in a CD situation you would ordinarily resign straight after the breach and without giving any notice.
You also need to bear in mind the three month limitation period - if the sexual harassment acts were more than three months ago, and nothing has happened since that would extend that three month period, you could lose your right to bring that claim. However you could argue the outcome to the disciplinary was a further discriminatory act which could bring it all within time limits.
You also need to ensure that you exhaust the grievance and appeals process - if you don’t, your employer has the argument that they haven’t committed a fundamental breach as it could have been rectified through the grievance or appeal process. Plus, it would reduce your compensation even if you won (and if you walk straight into another job you won’t be entitled to loss of earnings compensation unless your new job pays less).
You really do need fast legal advice.