I live in London, UK. I need help.

15 months ago i started recovery for alcoholism and drug addiction. I am glad to say that i have not touched a drink or drug since, and have been clean and sober.
I feel stupid admitting this, since i have full working knowledge of a programme and how the 12 steps work, but my sexual behaviour has just totally gone unchecked. Where i was in such a mess beforehand, caught up in a cycle of using and drinking, it never occurred to me that my sexual conduct was really out of control.
I am in a relationship, i care for this girl dearly, and i really do love her.
I know enough to know that any addicition or habit that is severe enough, means that it matters nothing about how much you love someone, it all goes out of the window when you are an addict.
I watch porn daily, then, digusted, delete it all, rebuild my laptop, then gradually it creeps in. Lately i have found myself entertaining ex partners by sms involving inappropriate texts and conversations i should never be involved in. I often think about sex alot with exes, and i masterbate twice a day. I seem to be obsessing.
This only really became obvious once i put the drink and drugs down. I feel so stupid for not even being able to see this.
I know as an addict i will chuck whatever i can into this hole to fill it - if its not porn, ill be eating, if its not eating ill be spending, its driving me slowly insane.
Its harming me because i cant seem to get close to my partner on any level. I feel isolated. Watching porn and engaging in this behaviour gives me an immense thrill, followed by an almighty crash, and then disgust and total numbness.
I dont know if i have another recovery journey in me right now, i feel totally lost and totally helpless. Im worried that this addiction will lead me to a drink and vice versa. Im caught up in a web of rubbish that just doesnt make sense. please help.