The easiest way to lower the temps in your space is to insulate and shorten the exhaust ducts in your grow space, especially the exhaust for your portable ac. The way you have it set up now the ac compressor is getting too hot and will run only a short time before cutting off and then you are just recirculating hot air. You need to place the ac such that the exhaust is no longer than 6 feet and is so well insulated that it doesn't feel hot to the touch. Any other duct that's hot, like after your lights, should be insulated as well - you will need to buy new ducting that's insulated but it will pay off immediately.
Also be aware that since the portable ac vents outside the tent you are potentially venting smelly air - an alternate set up would be to have your carbon filter alone with a fan so it's recirculating air which will keep the air inside the tent from smelling instead of just treating exhaust air.