It depends on you and only you. Are you extremely hard-working, organised and passionate about your subjects? Did you do well in these subjects at GCSE? Are they relevant to whatever you'd like to study at university?
Be honest with yourself and then make a decision, remember that most sixth forms and colleges provide an option to drop any after AS, so if you find it too difficult to manage then that can be your plan b.
I have students who are did as many as 5 A levels with EPQs this year. It's definitely possible, but they're not the type to waste every weekend drunk or going out. They work incredibly hard and wait until the summer period to really enjoy themselves. Do you have that kind of discipline? Are you organised enough to stick to revision schedules?
Whatever you decide, best of luck.