The weed alone is way worse than the ciggs and you know they are bad. If you keep it up your lungs will be in bad shape soon enough. Get wise while you are young.
I am not qualified to tell you just how much damage you have already done, but what I will tell you is that if you quit today, a lot of the damage can be reversed.
Just the fact that you are concerned is a step in the right direction.
There is a website whyquit.com that has a section called "Motivation" and this deals directly with your question. It is very sad, but it speaks to us about the consequences of addiction.
I smoked for 38 years and the last 5 of those years I used an inhaler twice a day. I had little lung capacity left for climbing stairs, walking fast, anything other then a slow walk.
I have quit for 9 1.2 months now and I am happy to say that I have more stamina now and even jog a little : )
What I do know is that I feel so much better now then when I was actively smoking.
There is a Stop Smoking Recovery Timetable on that site which will explain the healing progress.
You are young so you need to stop while you have control of the situation. If you need moral support, that is what we are here for.
Good luck and keep us posted : )
Kahy Jo
p.s. read my stats below
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9m 2w 5d 11:16 smoke-free, 6,451 cigs not smoked, $1,548.24 saved, 3w 1d 9:35 life saved