How To Treat Swelling And Numbness In Hand After Injecting Meth?

If I believe I missed a vein while injecting meth how do I treat it so it won't do any further damage I cannot see a doctor for the next two days because of family commitments. Before I injected I pulled the plunger back and it registered I'm usually pretty good with hitting my veins but this time my whole hand went numb and It hurt petty bad now my vein is barely visible and slightly swollen. It's only been about 20 min..I just really would like to keep my hand lol