My backstory + overcoming an extremely bad urge.

You're no failure, proof is you wouldn't be there fighting for what you want most in life if you were.
You can already stop thinking of your previous streaks as "failed" (quoting you here), because there's no such thing. P(MO)-free streaks always ALWAYS bring something new to your journey, so they're never failed. Failure happens when we stop and look the other way without trying again.

The sad part is, when the feeling of being broken and ashamed arise, it mostly reinforces the addiction. Best not dwell in this feeling and try and replace it with something that doesnt feed that part of you. You can do this, I'm sure! You've done a couple of streaks, you seem well organized, and sporty, so these are already tools at your disposal, which many of us addicts can brag about yet.

As for prostitutes, "Rewiring with a real woman" is frequently discussed at NoFap forums, and there's a few good reasons for this debate. But you need to be able sense the difference between someone you care for and someone that's no better (I mean the quality of your interaction) than your average P clip. If it's instant gratification, then it's probably a bad idea. If it's investing in someone and in your relationship, then maybe it can be very beneficial to you while you change habits. But then again, this is wildly debated so I'm not gonna attract more lightning than I already have by saying that.

Your friend might not understand (AT ALL) what you're doing when you abstain from PMO, let alone know what you're doing when you abstain from PMO. Everybody here has faced friends that were looking at us like "wtf u talkin bout dude?" without knowing the pain and suffering we're going through (before and during reboots). It doesnt need to change your frienships, but when it comes to changing a cornerstone of your intimate life (which extends way beyond that as you're about to discover), maybe it can be a fair question to ask yourself when someone like that incites you to do things you don't want to do anymore. What influence does he have on you, and do you want to keep that alive (at least while you're rebooting). Just thoughts, I myself had to part ways with some friends that were like a block of concrete tied to my feet, preventing me to get my life's air at the surface. Changed my ways with them, told them why, they weren't interested in changing themselves (which is fine, it's a personnal choice), so we now have a different relationship that still produces moments that we both enjoy, the nasty stuff being reduced to a bare minimum

 

You are not alone.
Keep fighting, and I hope your friend begins to understand or that you find one who will.