Good effort, that's a decent shape to be in. 10k runs are my "thing" but as my march into middle age progresses, I find I can't do them back-to-back any more, I'm needing more than a day or two to recover.
Maybe go for something a little more varied - I'm training for (but never done) local triathlons. Great way to build physical fitness with only a third of the high impact on the joints. The major limiting factor will be the pool of course, unless you're fortunate to own (or have unrestricted access to) a pool.
Random turn of conversation direction, are you creative at all? Crocheting seems to make the world go by at an alarming rate - it's both a time killer and very rewarding.