Repeating the same sin again means that repentance was not real . Real repenting means you decide not to commit the sin again. We need to think on the results of the sinful acts and avoid it once for all. Seeking forgiveness needs a firm decision not to do it again. We need to face ourselves and tackle our sinful desires because we will be in serious danger if we don't leave the sinful acts.
Seel help from Allah (SWT) to enable you to defeat Satan and sinful desires and repeat ASTAGHFIRULLAH RABBI WA ATOOBU ELAYH. But no foreguveness if keep on committing the sins.
Wassalam.