Aphids suck

Try cinnamon or cyan pepper water mix. Shouldn't hurt the plant but most bugs hate the stuff.

in summer the aphids cannot stand the heat and die, but it is not that hot yet, I would recommend neem oil or potassium soap and 2 times a week to prevent them from reproducing, spray the branches and stems well if I tell you the truth I also have aphids and honestly it is impossible to disappear all of them but if you spray even 3 times or 2 per week to keep them controlled, and wait for the plant to become strong and that they cannot bite the stem or leaf, since they are always in the newer shoots, and small ones like the lower ones or the new ones above, and I would also recommend sulfur that kills any bug, but always with control since they can create resistance to insecticides

there is no fast solution that I know, but I can advise 3 things you should do: get some diatomaceous earth and sprinkle it in on the top soil. Also in your soapy water mix for spraying, add some diatomaceous as well. Second, continue with the spraying. It takes many sessions to get rid of them. Third: fumigate, you can do this even with incense under the leaves. They spread very fast and in large numbers, so takes time and persistence but it's not imposible.