Well, I'm not sure what the hype is all about. I mean aren't most students taking 3 A-Level subjects these days? Anyhow, I have 5 A-Level subjects myself--Physics, Chemistry, Biology, Math & Urdu. And I'm not splitting them like you are (i.e. I'm sitting in the May/June session only) and though my board is CIE, I'm pretty certain that CIE Math is definitely harder than Edexcel Math, even if the rest of the subjects are considered simpler in some alternate reality.
So I don't think it's tough. What were your AS grades? If you managed an A or even a B, you should consider yourself on the the greener side of the grass.
Remember to avoid subjects you have no interest in, (I would incinerate Physics and the Physics teacher if I had the choice) but sometimes you have to make the sacrifice for career prospects. Usually, your subject choices are incumbent to follow into Engineering of any kind, so unless you want to complete your undergraduate degree in a singular subject (e.g. Bachelors in Chemistry) then you can't avoid any of these subjects. Best wishes with your future!