If it takes more and more alcohol or more and more drugs to get the same effect, you know you have a problem. You're saying the reason for drinking or drugging is to relieve painful feelings or to get high. You're trying to get away from something negative and looking for something you think is more positive. After a while, the high won't get higher and you won't be able to get rid of whatever is bothering you. In the meantime, you will have become addicted and have that added problem to deal with before finding better and more positive ways of coping with your problems.
Blackouts are a major problem.
They are linked to all those extra drinks or to the large quantity you've started to consume. Now that you know this unpleasantness clearly, you start to worry about senility, your capabilities, and the blackouts. It leads you right back to a bottle to stop the worrying and the memory of worrying. It's an addictive cycle. Worry can be useful, but you don't have to do it alone.