Even 300’ in a few months is impressive to me. I personally can’t throw 400 but form work is probably what you need. Take videos of yourself from the side and behind and see what you can work on. There plenty of videos out there for you to learn from and compare. I would also recommend finding a pro who you think has a similar form and work to duplicate it.

Most important lesson I learned in DG, I learned early on: It doesn’t matter if you throw 50 ft further than the competition if they can make 50 ft putts.

For your 400 ft hole scenario, imagine throwing 425 long, you go OB, pull it back in, miss the putt, hit it for 4. OR, you throw 300 nice and controlled, little putter upshot of 100’, drop in for 3.

Drop that down to a 330 foot hole and throwing 300 and hitting a 30 ft putt gets you a 2, throwing 350 and missing the 20 foot comeback gets you a 3 at best, probably worse if you have an “interesting” green.

Practice driving if you want, but working on upshots from 50-100 feet and putting out to 20, then 30, 40, 50 ft will make you a SIGNIFICANTLY better disc golfer.

All that said, if you really want to increase distance, know that it’s all about speed, not necessarily strength. You also need to be smooth. Slow is smooth, smooth is fast. Watch some YT tutorials from a normal sized human like Dave Feldberg, especially older stuff from him, or maybe watch some of the ladies who throw well. Learning how to throw far from Big Jerm or Shoestring doesn’t help as much (at least for me) because they can do almost everything wrong and still throw far because they have 7 foot wingspans, LOL. Feldberg is 5’11".

Oh, and make sure you’re throwing the correct disc for your current arm speed, and one with plenty of glide. Try something slow with a lot of glide like a Kite. It’s kind of flippy. If you throw it flat and it flies straight, you don’t have the speed for a driver yet. When your Kite gets flippy, try a fairway driver like a Leopard or Cheetah. When those get flippy, try a Valkyrie or Roadrunner. You should be hitting 400 with a Valk or Roadrunner before trying anything faster or more stable than that.

Also check your disc weights. Only throw max weight mid ranges and maybe fairway drivers, or if you really need something overstable to fight a headwind. You’ll probably want a 150-160 class leopard/cheetah and a 150-160 Valk/Roadrunner to start with to get that extra float.

Finally disc plastic as that ties into weight. Champ/Z plastic is super overstable and takes forever to beat in and give you the S curves needed for distance. Champ and Z are also awful for your grip. If you need something premium for durability in the woods try Star/G Star and ESP/ESP FLX or equivalents. For long bombs in the open, look for DX or Pro or equivalent. It’ll give you better grip and beat in a bit for more glide and longer throws until it eventually gets too flippy.