Patience. It will take time, and will be difficult sometimes. Be patient. Be determined. Do a little at a time. Set yourself a little goal each day/week.

Read and speak as much as you can. Keep a diary in English and ask Italki members to correct your mistakes. Do regular revision of grammar and learn five words a day.

memorize words and exercise grammar

For vocabulary focus on the words you use everyday first. Especially the "glue words" like (and, the, then,than, to, too, but,). Just like en español usas los palabras que, como, entonces, pero, mucho tiempo cada día. A general tip, just try to communicate first. Of course you will make mistakes, but the number one goal is to communicate. Then when you correct mistakes focus on one at a time. If you try to be perfect on everything and correct everything you will improve very slow, or not at all. Since you are learning alone at home it is very important to speak with your language partners. Conversational ability can't be done alone. Listen to a lot of English, so you get familiar with the sounds, and rythn.