You really shouldn't cut yourself at all and maybe try to find safer ethical ways to source the blood (like from like a local butcher shop or something)

But lol yeah if you're gonna insist on cutting yourself you'll want clean first aid supplies. If it escalates you should definitely seek help.

Try learning about water color and/or caligraphy techniques and practicing using traditional paints/inks before incorporating blood again. The way colors react to water and the timing involved with the process is really interesting and you'll probably see similarities to whatever it is you're doing.

Then if you REALLY want to - you'll make much better use of blood when you have an actual project in mind that people will be more open minded about. Otherwise it might come off to most people as a sort of mall goth gimmick where ppl are gonna focus on and worry about your mental health instead of whatever you're making.

tl;dr Basically try to make something where you can be like "oh btw that's blood" in passing. It will have a much greater effect accenting an existing work rather than being the central focus of whatever you're drawing/writing.