The best thing you can do is get a Talaqnama prepared by your Maulavi/ kazi, inform him what had happened between you. A talque pronounced cannot be taken back. Under sharia law you are divorced , so no other law available to you as a Muslim to go for again a divorce.
According to Sunni law, a talaaq, may be oral or in writing. It may be simply uttered by the husband or he may write a Talaaqnama. No specific formula or use of any particular word is required to constitute a valid talaaq. Any expression which clearly indicates the husband’s desire to break the marriage is sufficient. It need not be made in the presence of the witnesses.
According to Shias, talaaq, must be pronounced orally, except where the husband is unable to speak. If the husband can speak but gives it in writing, the talaaq, is void under Shia law. Here talaaq must be pronounced in the presence of two witnesses.
The words of talaaq must clearly indicate the husband’s intention to dissolve the marriage. If the pronouncement is not express and is ambiguous then it is absolutely necessary to prove that the husband clearly intends to dissolve the marriage.
Since you have pronounced talaq go ahead and continue withe the procedure to give a written intimation along with the mehar amount if you have not paid already and a cheque of idat period. It could be an affordable amount by you to your wife for 3 months maintenance . Talaq legally cannot be completed without the formal payment of Mehar and idat .
Once you do this her claims of threat and blackmail will have no stand. so go ahead and finish it before things worsen.
Why should you file any petition to bring her back if you do not wish it, yes you have a legal option to file RCR (Restitution of conjugal rights)under civil procedure code to ask her to join your marriage, but what about your talque which already pronounced, so it is advisable not do anything against the existing sharia law as you are guided by sharia law in the court as well. where as your wife has options to ask for a divorce under The Muslim Women (Protection of Rights on Divorce) Act 1986 and other provisions in different other common Acts which are made for married women
talk to a Maulavi/ kazi get a talaqnama done send it along with an intimation notice either by your lawyer or the same kazi along withe idat period and mehar amount cheque.
Do not give into the pressure to her black mail and threat. once you finish the procedure of Talaque she will not be bale to continue with her complaints as a divorced women stands with no right other than mentioned in sharia law,