Oh sorry @DaztardlyAriel I wasn't saying hit 70 kilos straight away! Just that you'll surprise yourself if you keep trying. People can lift a lot heavier than they think (me included).
|I think you need confidence more than anything. It took me ages to get over the mental hurdle of a really heavy lift. Nowadays, because I know that I can rep out a heavy deadlift, I get it done more easily. Go figure ...
I'm still not clear about your current lift, though - is the whole bar + weights 20 kilos?
Keep going, but try to add weight onto that 20 kilos (or is it 40 kilos?) - just another 1.25 kilos each side, and then another 1.25, and so on. (At my gym, we have the teeny tiny plates that weight 500 grammes - I've used those to keep pushing up my 1 rep max!)
@RayKray 's suggestion of kettlebells is a good one for building strength, but in my experience, they feel heavier than a loaded bar! My PT has me doing farmer's carry for a minute with 2 x 32 kilo kettlebells, and that is far far harder than a set of deadlifts at 64 kilos. They're far less stable.
So maybe try with 2 x10 kilo KBs, and then go up to 12 kilos? then you're doing more than 20 kilos, so you build confidence, because I bet you're already strong enough to lift more than 20 kilos. And if you can do it with kettlebells, a loaded bar of the same weight will seem much lighter!
Have fun. It is the best feeling in the world, lifting heavy stuff up off the floor - I'm over 65 and I can deadlift 1.5 times my bodyweight. It took me a year to get to bodyweight, and then 6 more years to get over 100 kilos - but if I can do it, anyone can, particularly if you're younger. You get such a strong back and legs - useful in everyday life, especially if you're travelling.