You are going to want to consolidate your UTXOs into one address. Make a transaction for your entire balance and send it to a new address in the same wallet. Set the fee to something low like 10 sats per vbyte. It will take a long time to confirm, but it should go through eventually. Once you have one big UTXO you will only be paying the minimum miner fee to spend from it later when fees are likely higher.

Just try creating the transaction now to see what the fee is going to be. You don't have to send it yet, but it will give you an idea for what you are dealing with.