Asalaamu Alaikum,
My sister we should have certainty that Allah will listen to our Dua's as he hears every Dua we make to him. This is especially the case during the times when Dua's are accepted the most like in the last 10 Nights of this blessed months during the latter part of the night.
We must also have hope that our Dua's will be accepted. However we must also realise that sometimes Allah accepts Dua's in other ways that we may not understand right now in that he may open up other doors for us etc. So we must have trust and faith in his wisdom and never lose hope and patience:
The Prophet (Sallallahu Alaihi Wa Sallam) said: “The slave will receive a response so long as his Duaa does not involve sin or severing of family ties, and so long as he is not hasty.”It was said, “What does being hasty mean?” He, Sallallahu alaihi Wa Sallam, said: “When he says, `I made Duaa and I made Duaa, and I have not seen any response,’ he gets frustrated and stops making Duaa.” (Bukahari, 6340; Muslim, 2735)
With regards to our sins then must also do our best to change our condition ourselves as Allah says:
Verily, Allaah will not change the (good) condition of a people as long as they do not change their state (of goodness) themselves (by committing sins and by being ungrateful and disobedient to Allaah)” [al-Ra’d 13:11]
Certainly he will give us many opportunities. But if we fail we must keep asking of him for forgiveness. However if we continue in the wrong path then we may be suddenly seized:
"So, when they forgot (the warning) with which they had been reminded, We opened for them the gates of every (pleasant) thing, until in the midst of their enjoyment in that which they were given, all of a sudden, We took them (in punishment), and lo! They were plunged into destruction with deep regrets and sorrows” [al-An’aam 6:44]
Or it maybe that many of us are given respite until the day of Judgement for our wrongdoings:
“Consider not that Allaah is unaware of that which the Zâlimûn (polytheists, wrongdoers) do, but He gives them respite up to a Day when the eyes will stare in horror”[Ibraaheem 14:42]
So we must seek refuge in Allah for our wrong doings and ask of Allah not to punish us in this world or the next. We must keep striving against our nafs and be in constant repentance as Allah loves repentance. We must never lose hope in the mercy and forgiveness of Allah:
In a beautiful Hadith Qudsi, in which Allah himself says:
"Even if your sins were to reach the clouds in the sky, I would forgive you".[Sunan al-Tirmdhi]
Allah also says:
"Say: O My slaves who have transgressed against themselves (because of sins), do not despair from the mercy of Allah. Verily, Allah forgives all sins. Verily, He is All-Forgiving, Most Merciful." [Al-Qur'an 39:53]