How quickly do I start after a break due to illness

[PhoebeMcPeePee]

Up until 5 weeks ago my week consist of 2 HIIT classes, a 6/7km run and 2 30-40km bike rides. Illness followed by injury has put me completely out of action but to my usual routine (and lose the half a stone I've gained ) but am slightly wary about overdoing it and injuring myself again.
Do I just stick with my usual routine but at a slower/easier pace for a few weeks or should I look at starting with some strength building maybe swimming or weights? I honestly feel like every muscle has turned to rubber and could barely manage a single press-up when I did a little set at home this morning . Any advice?

Bloody hell I wish there was an edit button hope you can make sense of that rather jumbled post

I'd start with swimming, then add self paced things like running/ cycling at a lower intensity and distance than usual.