You can request a steroid injection into a muscle, but this might only be available through the consultant; it'll be worth it to try and get the money to see the private one again, request an im pulse and ask if he can transfer you to his NHS list if he works in the NHS at all or refer to a colleague who does.
Oral steroids can help and would be available through your GP, but they have greater side effects and cannot be discontinued quickly, whilst the injection wears off gradually (they're bloody amazing for stopping a flare like you're having now in its tracks, though).
You need consultant care to access DMARDs - take them, go through the process, ask for referrals for physio, for podiatry, and try to get onto Biologics asap.
Other things that do help are swimming/moving around in a pool (you still need to exercise, the water helps by cooling and supporting inflamed joints and tendons), the controlled situation of resistance training in the gym - machines because you can sit down and start with the smallest weight possible, rather than do the lifting heavy barbells thing that will put you at risk of injury compared to somebody who doesn't have PsA - a lot of braces and strapping, wearing proper running shoes with arch support inserts (shoes from a running shop, probably in a larger size than you thought you were), being careful of posture, eating healthily and making sure your bed is supportive and your pillow keeps your neck straight (I like the IKEA shaped pillow for that). I needed a memory foam topper on my mattress or I'd wake up in pain far more often - I now need to replace the mattress, but the topper did the job for ten years.
The inflammatory process puts you at higher risk of cardiac issues and diabetes - keep your cholesterol and blood sugar low and eat oily fish twice a week, lots of vegetables, pulses and meat that's 'a bit of a animal' rather than heavily processed. 'Diet' food is lower calorie, heavily processed shit, but appropriate amounts of less processed items give you nutrition. Make sure you have enough Vitamin D by supplementing throughout the year. I also take a multivitamin (with folic acid since I started Biologics, without when on Methotrexate but replaced by high dose folic acid on non methotrexate days as per consultant prescription) and Magnesium.
Whilst your joints may see less damage over time, something that can be affected severely is the tendons. So ensure the joints that do the most work are well supported and able to function smoothly - good footwear and supports protect your Achilles and arches, then help to reduce strain on your knees, hips, lower, mid and upper back, shoulders and neck, for example; it's a chain that relies upon all parts being right, which means get the feet right and posture follows.
If you go onto the Versus Arthritis website, you can read their advice booklet on PsA.
Finally, you'll likely have people not understanding that it's not wear and tear arthritis and it isn't Rheumatoid, including medical staff. Get informed and advocate for yourself - it's fine to say 'This isn't sustainable/it's not working/it's helping but it isn't enough, so can we look into other medication/treatment sooner?' And when you get the 'Have you considered that you think you're in pain because you're depressed?', don't rip their heads off, mainly because you'd leave a trail of decapitated idiots wherever you go, but point out that uncontrolled inflammatory processes and pain are both known to cause symptoms that are frequently mistaken for depression but they can instantly resolve with effective treatment for the disease process.
It can feel hugely overwhelming at first, especially in a flare, but once you're on something that works, it's amazing to feel the difference.