I guess that the main problem with stims is vasoconstriction, I can't imagine how they directly would cause thrombosis but vasoconstriction can precipitate them. So you'd need a vasodilator, but that's as Perforated said, beyond of what we can do anonymously over the net. I also guess that a low, therapeutic dose of meth like 5-10mg should be of less harm potential than a full MDMA dose but that doesn't mean that it's safe. Really dependent on what the origin was of your blood clots and if this origin is still present etc. here you need an open-minded doc.