19 days without PMO starting to struggle need help

Hi, this is my first time posting anything to nofap, however I've been reading threads on here for several months now and have had some small numbers of days of abstinence of pmo.

As of right now I am on day 19 without any "self induced" orgasm (as I am in a relationship total sexual abstinence is not an option )

I've been watching porn since aged 9/10 and always knew it was unhealthy behaviour however never knew any different.

I am at the minute finding it very difficult not to "peak" at porn channels on TV etc.
I have looked several times and quickly changed stations. The guilt that overwhelms me when I have fapped in the past is terrible I become so depressed and disheartened in myself and it affects my relationship with my girlfriend who I love very much we are expecting a child in September.

I have been taking the last few mins of my shower ice cold every day as I read on here that it helps?

when the urge to look at the porn channels comes how do I be more strong mentally.

Sorry in advance if this is not the usual format for a post of this nature.

any responses greatly appreciated thank you.