I guess you'll know by now the mempool has been bloating up, with no end in sight. I've experienced several congestion periods this year, but probably none as extended as this. Check out this estimator to have an idea of how long your txs will take to confirm :https://bitcoinfees.earn.com/
These estimates will only increase as mempool grows, they will also come down if the network eases up.
So, are current levels, any tx with a fee below 401 sats/byte (!), expect them never to confirm unless mempool comes down. At 732 sats/byte, if the situation holds, you'll get a 90% chance of confirmation within the next 5 hours, so I think you're "safe" on that. BUT, since the higher fee needs the preceding 2 txs to confirm first (since it spends unconfirmed outputs in a string of 3 txs)... you've no choice but to wait for the earlier ones to confirm.
Your options now are to attempt a CPFP, making one more transaction using the same linked outputs, including fees to pay for all. Mycelium should support it, though I'm not sure if you can link 3... essentially, you're doing a child pays for parent and grandparent
Or, more painstakingly, seek help from an acceleration service to confirm the 1st, then second. You can keep trying yourself on the hour every hour, submitting to
https://pool.viabtc.com/tools/txaccelerator/ but you're going to have to get lucky as they only accept 100 every hour. Try about 5 mins before the hour.