I have been advised by several confessors, that in struggling against this habitual sin, that as long as I am genuinely trying to repent, that if and when I fall I should not let it keep me from the Holy Communion. I should make an act of Contrition, ask Gods Help, and carry on until I can next get to confession.
There is a ballance to be had here, and it is your confessors job to advise you, but the
Catechism explicitly gives guidance on this matter for confessors and councellors:
2352 By masturbation is to be understood the deliberate stimulation of the genital organs in order to derive sexual pleasure. "Both the Magisterium of the Church, in the course of a constant tradition, and the moral sense of the faithful have been in no doubt and have firmly maintained that masturbation is an intrinsically and gravely disordered action."138 “The deliberate use of the sexual faculty, for whatever reason, outside of marriage is essentially contrary to its purpose.” For here sexual pleasure is sought outside of "the sexual relationship which is demanded by the moral order and in which the total meaning of mutual self-giving and human procreation in the context of true love is achieved."139
To form an equitable judgment about the subjects’ moral responsibility and to guide pastoral action, one must take into account the affective immaturity, force of acquired habit, conditions of anxiety or other psychological or social factors that lessen, if not even reduce to a minimum, moral culpability.
This makes it clear that when struggling against an acquired habit, and the strong hormones of your late puberty, and the teachings of the secular world in this matter, as long as you continue the struggle, and are Trying to quit, your personal guilt in this matter is most likely to be Venial not Mortal in nature.
That does not make it OK, it does not mean you can choose to sin knowing you will confess it later.
You should go to confession if you can, but you are probably OK to receive Holy Communion on Sunday if you are unable to Confess today or tomorrow.