Hi Lost Pilot.
First of all, good on you for seeking out information and trying to solve your dilemma.
Second of all, there's been some excellent advice already. Like REALLY, REALLY good.
Third, my humble opinion:
1. Slatye has hit the nail on the head. If you're actually only 15 hours from the standard, just persist. Have a chat to the CFI, if he thinks you're still a long way off, maybe shelve it for the time being. Ask for a different instructor - it can make ALL the difference.
Even the CFI might do a few flights with you to ease your mind. The friendliest, MOST FUN instructor I've ever flown with was my CFI.
2. The financial pressure can be a real burden, but remember it can be paid off. Even if you finish the last 15 hours and decide to work outside of aviation for a while, if you're disciplined and work hard you'll pay it back quickly. I paid my CPL and MECIR off in under two years. Turnbull can wait, he's got enough already.
3. Regarding the big D, the best advice I can give you is to go and see someone. I've seen a few mates struggle at times, and every single one has delayed seeking help. They've torn themselves to pieces for a very long time, and yet once they've finally looked for help - the improvement has been very strong and fast. Every person I know that has been down this road has eventually regretted not seeking help much earlier.
21st century men are no longer expected to dampen their feelings, pretend it's okay when it's not - or concern themselves with what their mates might think. Anyone who doesn't support you when you're struggling isn't a mate anyway.
If you see your GP then they can talk to you about it, and if further investigation is warranted medicare will pay for up to ten mental health sessions so you can get back on the right path. In the event help isn't needed, it will ease your mind that you're okay which is a huge step towards feeling better.
a) Go and see your CFI, that's what they are there for
b) Go and see your GP, if for nothing else than to tick a box and confirm that you are coping okay
c) You don't need an instrument rating for your first job. Worry about it later.