What might I have done to my ankle & what can I try to fix it?

[ahagwearsapointybonnet]

I've been having some trouble with my ankle for over a week now, but not sure what it is or what's the best way to try and treat it, can anyone make a suggestion? It came on after I increased my exercise a bit - although I was trying not to overdo it, and don't think I did that much really (did a bit more running than before, restarted 30-day Shred - but taking it easy as it was my first few sessions - and a bit of dancing, but all with rest days in between, and nothing ridiculously excessive). I don't remember doing anything to it specifically (no accidents or anything, and it came on gradually not suddenly). Main symptoms are:

The painful bit is on the inside of my ankle, about 1 1/2 inches above the sticky-out bone (technical term). I can feel it a little when I'm active, e.g. walking, but mostly it is tender when touched and is now really quite sore if it gets pressed. It's not noticeably swollen to look at (maybe a tiny bit?), but it feels like there is possibly a bit of a lump under there if I press it. Also that ankle sometimes feels a bit weak, for example if I stand on one leg, or when walking it sometimes feels weaker than the other one.

I should also mention I had a similar thing once before, but never really found out exactly what caused it that time either, or exactly what was wrong. I did see a physio for it, but she didn't seem completely sure what was wrong either, although I think she had a theory that something higher up (below my knee) might be tight. I'll go back if necessary, but last time it took quite a lot of visits and £££ before it got better, and it was hard to say how much it helped vs. just getting better by itself. So I would like to know if there's anything I can try at home first (heat/cold, massage, exercises, rest??) before going again. Also would like to know whether gentle exercise is likely to make it worse or better, and what would be good to try? As I was just starting to get back into a routine, it's really frustrating having to stop already, especially as I was trying hard to be sensible and not get injured!

Apologies for the multiple posts by the way which are to get around paragraphs not working at the moment! Also I forgot to add, I did try one very short/gentle run just to see what effect that would have, and found it was not particularly painful while running, but did get a bit more tender straight after. I really want to get on with some more exercise, but at the same time don't want to make it worse of course! So any advice is very welcome.