A double on leaden legs

So, 2 days after a 20 mile run, and 1 day after a fairly painful sports massage, I didn't sensibly reassess my training plan, and instead stuck to it.  3 miles easy in the morning.  9x400m intervals in the evening:

So, 1st session in the morning was 3 miles easy- avg pace 9:48mm, then I played with my new kettlebells for a while after.

The second was a session I did a few weeks ago, with an extra repeat  9x400m with 90s rest.  I decided to jog some of the rest intervals, but looking at my times, its obvious my legs are tired, as they were much slower than last time I did it!

I did 4.66 miles in total, including the warm up and cool down, and interval paces were as follows:

Interval 1: 6:34

jog

Interval 2: 6:57

walk

Interval 3: 7:15

jog

Interval 4: 7:20

walk

Interval 5: 7:10

walk

Interval 6: 7:02

jog

Interval 7: 6:53

walk

Interval 8: 7:25

jog

Interval 9: 7:02

In the cooldown I felt my calf really trying to tighten, so I stopped and walked home- didn't want to risk a new tear   so these paces are quite a bit slower.  Wonder whether I should have listened to my friend's advice to have an extra rest day before doing speed work, or whether I will still realise some benefit from having done this session even if the speed isn't as much as it was last time I did it.

Yesterday I was having high hopes that I could go for a London GFA qualifying time in my Spring marathon if I'm sensible about my training from now, but today's session has knocked my confidence a bit  so I'm doing more training for Bacchus half, with a glass of red