You didn’t say how your were "picking" stocks but if they have been going down, you definetly not picking them properly ot at the right time.
One of the basic rules, especially investing short term, is you never buy against the trend. If the stock is trending down, you don;t buy., A company can have the greatest fundamentals in the world but if it;s in a down trend you will loose

Before any trades/invests they must have 4 important items in place before they enter their first order
1 – A written sound trading/investment plan with rules that will not only help you but more importantly protect you, mostly from yourself.
2 – Sufficient trading/investment capital. Use your own money, there’s no need to go into debt so that you trade/invest.
3 – A written money management program in place.
4 – A full and complete understanding of the rules & regulations of the industry.
.
Since you didn’t provide your criteria for selecting investments here are some rules you could follow

The first and primary rule should be never enter into a trade without knowing when and where you’re going to close the trade.

Never invest on emotions; feelings have no place in determining investments.

Only buy stocks with real sales and real earnings, does not apply to pennystocks since they are crap shoots and are traded as fun things and not as investments.

Only consider buying stocks with each of the last three years’ earnings up 25%+, return on equity of 17%+ and recent earnings and sales accelerating.
Avoid cheap stocks, buy only higher quality stocks selling $10 a share and higher.

Never buy if the firm is filing or in bankruptcy.

Learn how to use charts to see sound bases and exact buy points.

Stay with up trending stocks, never buy on down trends. This does mean “the trend is your friend”.

Always buy companies with new ideas, styles or products.

Cut every loss when it’s 8% below your cost. Make no exceptions so you can always avoid huge, damaging losses. You can always average “up”..

Follow selling rules on when to sell and take profit on the way up.

Never average down

Always sell when management cuts sales or earnings forecasts

Buy when market indexes are in an uptrend. Reduce investments and raise cash when general market indexes show five or more days of volume distribution.

Pick companies with management ownership of stock.

Select stocks with increasing institutional sponsorship in recent quarters.

Current quarterly after-tax profit margins should be improving, near their peak and among the best in the stock’s industry

Don’t buy because of dividends or P-E ratios.

Go to Zecco.com and open an account with them after that buy RITE AID STOCK, (RAD) their stock is as low as 2 dollars and if you hold it for a couple of years you will make good money. This stock is going to jump back up because Rite Aid owns all of their real estate stores and do not rent their locations like WalGreens and CVS Pharmacy

stock prices you see only reflects the reactions of the company to its environment. It could be predicted if you know the whole story to why it went down, up, or stayed still. That’s alot of investigating. Hey just look at legislation in states that are about to pass, predict its capacity in commerce, and follow the sectors it will mostly impact. Then look at the companies it will impact. this will be your blue print to your success. For example, when smoking was banned in Los Angeles 2000. yeah there are a bunch of smokers and they are not going to quit, so they go outside to smoke. It is cold outside where they can smoke so, lets get them a heater. Those tall metallic lamps that you see in all restaurants patios were not there prior to 2000. An industry was born on that date. After L.A banned smoking New York did a few year later, now Las Vegas is going that way. Just think of how many units are out there now, so legislation is a huge indicator of fortunes to be made. This is how Old money was made in the USA.

Listen, most likely you are purchasing near the top probably when you hear a good news bit. At this point stocks are typically over valued. You need to focus on several aspects of stocks. 1) their value relative to their competitors and their historical value 2) financial health 3) future prospects 4) any other macro economic elements that play a role in the stocks future performance.

Do not try to day trade, do not attempt to trend trade, pick an undervalued stock and hold it until you believe its hits its fair market value at which point liquidate. Lastly, resear, research,research. This game is all about patience and research. Do not panic when times are declining, this just opens windows for great deals. Good Luck!

Many people focus on how to pick stocks. They are doomed.

Success requires a complete plan, including rules on when you are going to exit the trade and money management, so you don’t get wiped out on a few trades. Your own description of your trading tells me that you are hanging on to your losers too long and possible are risking too much on each position.

Picking of stocks, no matter what ever you have picked-up but it is revel by your question that you have chosen mid term trading .Any smart investor like to invest in long term trading and it is beneficial to you.