Sounds like you weren't "investing" you were "trading". Investing should mean you put money into something like a total stock market index fund on a regular basis and forget about it for about 30 years. Over time compounding growth means that every $1 you invest today should grow to something like $15-20 by the time you reach retirement. Put another way, every $1 you aren't investing for your future today is costing you $15-20 in lost opportunity that you will never be able to recover.

So the question you should ask yourself is should you spend $5k to go start this business project (not sure what type of business you have in mind, but 5k isn't very much) or would you rather have $75-100k in the future if you invested the money instead?