Its so frustrating because every time I try to hit a high note my larynx rises and feels like a ball clogging my throat up, which stops me from singing to my full potential. Can anyone please give some advice?
An exercise that I learned from a voice teacher that was very focused on taking untrained singers to their "next level" (although she was a Wagnerian-level soprano ;-) might address your issue. It helps you get the throat "out of the business" of making the tone, instead creating the pitch all the way from the diaphragm (and lower). This way the larynx, et al, can stay relaxed as you climb in pitch, instead of clenching.
I'm not sure I can convey it only with words, but I will try:
My teacher called all this the "THE-UHs". It sounds pretty complicated, but once you get comfortable with the "bellows" work, the focus on relaxing your throat can be added later. You are aiming for high notes that have strong, firm support from lower down in your body, but a completely relaxed throat - feel your larynx with your hand!
It seems that you may be describing the action of constricting your vocal chords to "squeeze" out a higher note. I am not a professional vocalist, but I would like to attempt to give you my understanding of vocal technique from a choral perspective at the college level.
In any musical endeavor, technique is very important to prevent harm. Most musicians use their hands to make their music, and so are at risk for carpal tunnel syndrome. Louis Armstrong, the famous jazz trumpeter, managed to injure his lips through poor technique (For this source, search "embouchure" after expanding the bio). And just recently, Adele underwent vocal surgery for the nodules she developed in her vocal chords after years of poor vocal health. Suffice to say, you want to get this right.
That being said, technique generally works by limiting harmful techniques. In music, this generally means staying relaxed. Your neck is no different from a pianist's forearms in this case. You need to avoid "squeezing" the note out of your throat. It's what I believe is causing the feeling of your throat closing up; you're literally squeezing it closed with the muscles in your neck!
It's at this point that my discussion of vocal technique becomes less authoritative, and I am frankly unable to vouch for the accuracy of what follows. I'm merely passing along what I've been told by professionals.
You can imagine your lungs and throat to be a balloon filled with marbles (where the marbles represent air molecules). To hit your high notes, you need marbles to flow out of your mouth faster. There are two major ways to do this: you can squeeze your throat closed, or you can squeeze your lungs harder. Squeezing your throat will result in progressive damage to your voice over decades. Squeezing your lungs will cause less damage, which likely will not accumulate noticeably. Keeping your chest open and breathing deeply (yoga breaths; your stomach should move away from your spine when you inhale, and move towards your spine when you exhale) make this process much easier.
In short, my advice, in the most cynical light possible, is "don't do that". It's obviously not effective for singing at the level you're attempting, and it's dangerous for your voice. To achieve a similar effect, relax your throat and breathe deeply. You'll find at first that it's very difficult to sing without tensing up. You'll likely have to re-learn how to sing without that tension. If this advice is not enough for you, you'll probably need to have a voice teacher evaluate your technique and give some instruction. Good luck!