There are a lot of circuits in there! Another possibility may deserve a mention: maybe you can identify a few that could be combined, for example that primarily serve lighting which has been converted to LED and draws mere amps. You could take a pair of 15 amp circuits and with a pigtail feed them both from a single 15 A breaker. Could do likewise with a pair of 20 amp circuits fed from a single 20 A breaker. That frees up one slot. Find another pairing and you've got the two slots you needed. One would have to take special care if the combining involved any multi-wire branch circuits (could combine a third circuit with either side of the MWBC, but cannot combine the two sides of MWBC into a single breaker/pole). It appears there are none of those in your panel so this caution is just for the benefit of future readers.