bablu,
You have not had sex with the maid. Neither has she given you a handjob and masturbated you. So what is the problem. You can masturbate to your heart's desire and no should be affected by this. I feel you are not telling us the whole truth. Did you deliberately masturbate in the presence of your maid, so that she could see you and you hoped you would be able to entice her for sex.
Now, if she is blackmailing you, be firm in your resolve. Do not give in. Having sex with her would compromise your position and then you would have to give i nto all her demands - even marry her, if she makes a police case. The bond between you and your mother will be stronger than the bond between you and the maid, so do not be worried. Your mother will definitely take your side. Your mother may remove the maid from service, which will solve all your worries and problems. But I am not sure, this is what you want. Somewhere at the back of your mind, you have plans to have sex with the maid.
You may be a virgin. Is the maid a virgin? If she is not, then you need not worry, she will guide you how to have sex. We do not give TIPS on having sex with the maid. Please look for ideas some where else.