Gradle Startup Error "Could not reserve enough space for for object heap"

[WRDorval]

So I'm trying to mod minecraft 1.15.2 and but I can't seem to run the gradle build as it can't find the RAM to initialise the JVM. I played around with the gradle.properties file and it can only start when I allocate 1.2GB or lower despite having 9GB free of 16GB. I am 99% percent sure I successfully switched over to the 64bit jdk1.8.0._261 so I really don't know what could be causing the issue. I've attached screenshots of my user path, system path, aand the error message.
here's the result of for java -version

C:\dev\minecraft\Forge Test>java -version
java version "1.8.0_261"
Java(TM) SE Runtime Environment (build 1.8.0_261-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.261-b12, mixed mode)

C:\dev\minecraft\Forge Test>javac -version
javac 1.8.0_261
 

[WRDorval]

Thanks a bunch, it looks like IntelliJ had defaulted to the 32 bit version, you're the best, your respones on other threads have helped me out a bunch already