Hi @Sophilina,
I'm about 10 weeks out from a mastectomy with immediate implant reconstruction and 2 nodes biopsied all on my right (dominant) side. The reconstruction part of my surgery would be more complex than yours, but it was over-muscle, so not too bad. However my lymph biopsy is a smaller surgery than your clearance. So maybe that balances out?
Anyhow, I'm 45 and got my full range of movement back within 2 weeks. Could drive within 4. Like you I just got the sheet of exercises (I was too drugged out and in pain when the physio saw me the day after surgery to try them with her or even take in what she was saying.
Now at 10, apart from twinge-pains and tenderness/ouchy if pushed/bumped on the underarm region, I'd say I'm functioning pretty normally. I'm still avoiding really heavy lifting (but can let my 26kg 8 year old monkey climb on me again). Normal lifting like grocery bags etc is fine. My breastcare nurse said to make sure to do the stretches when I spend time on the computer or anything where my arms are quite still, and to take breaks regularly.
I saw my plastic surgeon last week and got the go ahead to return to archery and yoga (I don't think I could downward-dog yet as I'm no featherweight!). I've started doing theraband stretches that are akin to drawing a bow and they are fine. Hoping the weather is good to get on the course in a week or 2.
I paint and decided to give non-dominant hand painting a go. It was a great experience and, like gardening can be, great for keeping me sane through all this! I don't know what I would have done if I was someone without a home based hobby.
So I just wanted to reassure you that, while you may need to modify the way you do things for a while, gardening should be good to go soon!