What should I do to uphold my covenant with Allah and not break it after my repentance and regret for my sin, and what are the consequences for one who breaks their covenant with Allah, and what must I adhere to in order to be a chaste, believing girl?

You have been extreme in your covenant with Allah not to look at or speak to any man. It would have been more appropriate to restrict this to unlawful looking and speaking. If your covenant was a vow or an oath, its expiation is the expiation for an oath. A Muslim should neither be extreme in their religion nor be lenient, for extremism is forbidden. Seek forgiveness from Allah for breaking the covenant, and if you intended it as a vow or an oath, then the expiation for an oath is due upon you. For true commitment, perform the obligatory duties perfectly, avoid sins, and then perform as many voluntary acts of obedience as you can without hardship. You must also adhere to modesty, shyness, chastity, and keep company with those who help you maintain your commitment.