Before coming directly to your question, let me first state the ruling on masturbation:

Masturbation is generally considered forbidden in Islam since it is deemed to fall under the category of sexual satisfaction outside the framework of marriage.

According to the Qur’an, those who seek fulfillment outside the framework of marriage are deemed transgressors. (See the Qur’an: 23: 7). While explaining this verse, one often finds the commentators listing masturbation under the list of the forbidden categories of sexual fulfillment.

What we have stated above is the generally accepted view. However, according to some scholars, if a person is so tormented by his intense sexual desire or craving that he fears falling into zina (fornication), in such a case, masturbation is permitted as the lesser of the two evils. His case may be compared to that of a person who is permitted to eat pork because of fear of death by starvation.

However, having mentioned the above, we must state that one hardly needs to resort to it when we recognize the relatively flexible approach towards marriage that Islam adopts. Unfortunately, against the clear teachings of Islam, marriage has been rendered another difficult process today due to warped customs and conventions and undue expectations. When we approach marriage from the point of view of pristine Islam, we shall find less and less people being forced to exercise the above type of exceptional rulings.

If therefore you are unable to get married for reasons beyond your control, then you need to ask Allah for forgiveness. Allah is Merciful. There is no need for you to despair of Allah’s mercy. For no matter how ugly our sins are and how many times we sin and fall, if we are truly remorseful and turn to Allah, He will open His doors of mercy. Here is a sacred hadith that the Prophet (peace be upon him) narrated from his Lord: “A servant (of Allah) sinned and turned to Him saying: ‘My Lord, I have sinned; so forgive me’; his Lord said, ‘My servant knew that he has a Lord who forgives and punishes for sins; so I have forgiven my servant’. Then the person remained in that state for some time, and returned to the sin again and he prayed as before and the Lord said, ‘I have forgiven My servant…’So the lesson to learn from this is that no matter how ugly our sins and how many times we have sinned, Allah is Forgiving as long we recognize the Lordship of Allah and trust in Him and turn to Him in repentance, beseeching His mercy.

For further details on repentance please refer to the answer linked below:

The Door of Repentance Is Wide Open