If your speed was amphetamine salts, you'll be okay if you have no diagnosed or undiagnosed medical issues as far as I know. I took about the same amount of addy last night actually. I'm prescribed much less, but the pharmacy overfilled my meds...... and I decided to bend the rules a bit by taking like 70 milligrams yesterday. Nothing crazy happened, just stayed up until literally 7:30 AM after having been incredibly and unusually productive all night...... then I only slept for like 3 hours (was tossing and turning for much of the night)..... pulled a similar all nighter three nights ago as well. So, I'm rather sleep deprived and residually tweaky at the moment as well.
And yeah, I know exactly what your saying about the racing heartbeat/palpitations. Mine was doing the same last night and three nights ago as I tried to "sleep" (e.g. toss and turn in bed with not a wink of actual sleep) myself. Nobody can really notice amphs that well on me, times I have taken 50 milligram doses of addy (like I did during last night's all nighter), no one could tell even when I was peaked..... was rathter attentive and focused actually. No guarantees, just sharing my experiences. But yeah definitely get a good sleep tonight if you can. And "speed" is a generic term. I was assuming you were referring to adderall or another pharmaceutical amphetamine, but if the "speed" you got was something else I can't say from personal experience what the effects are like. But perhaps even if it wasn't pharms, there's a good chance someone else on here took whatever you did.