You abandoned the ocean, all you had was a small glass roof and a single tree.
Your work is in existence, and some PROFESSIONAL tips:
You can eat kelp dry because they are found everywhere in extremely large quantities, all you need to do is cook it.
The door is your friend. Extraction in the ocean is very slow. however, you can take it with you, you can set it and exploit it because there will be no water in that 1×1 area, let you exploit it at normal speed.
Remember to use your sapling wisely because they are your only source of wood, but the problem can be solved really quickly just by creating number dough (soil from dirt) and put some Young trees, after you have more than 4 trees things are much faster.
Discover and loot shipwrecks, they have precious spoils and resources that you can’t normally be in the ocean, they are another really important source of wood.
You will use your brain better and think of ways to survive in this lonely body of water.