I don't know anything about Spain specifically but in general, appeals are useful if you want dispute a point of law, especially if no other avenue is available. An appeal is typically longer, more expensive and more complex than a fresh application and I really don't see how it would be successful in your case as the decision seems easy to justify given the facts presented to the consulate.

Do note that your situation may simply make it very difficult to get a short-stay visa, even if you did everything right in your application. The officer chose five different reasons to refuse it (when one is enough) and some of these reasons will be very difficult to overcome. The main hurdles for you are

• You are effectively unemployed. The consulate will not be swayed by your statement that you manage the family business if you cannot prove it and may still be suspicious even if you could do that. You didn't mention that in your list of mistakes so it seems you do not realise how damaging this is. It means that you cannot show how you got the money to pay for this trip but also that you have no financial incentive to go back to the Philippines and could be considered at risk of immigrating to Spain.
• You are in a relationship with a Spanish citizen / resident. This is behind the “reasonable doubts as to your intention to leave the territory”. Even under the best of circumstances, this also means you could be tempted to stay in Spain and works against you. Worse, some of the choices you made make it look like you wanted to dissimulate that fact to the consulate, which also make it look as if you had been trying to (mis)use the short-stay visa to move to Spain.

Fiddling with the details of the trip (sponsorship, means of travel, etc.) won't change anything to the fundamentals of your situation. Applying immediately will further confirm that you are desperate to go to Spain, which makes sense since your girlfriend is there but will still be treated as a red flag by the consulate.

There is nothing stopping you from applying again but from what you told us it sounds like you are in a difficult situation and a refusal is likely no matter what you do.

I don't know anything about Spain specifically but in general, appeals are useful if you want dispute a point of law, especially if no other avenue is available. An appeal is typically longer, more expensive, and more complex than a fresh application and I really don't see how it would be successful in your case as the decision seems easy to justify given the facts presented to the consulate.

Do note that your situation may simply make it very difficult to get a short-stay visa, even if you did everything right in your application. The officer chose five different reasons to refuse it (when one is enough) and some of these reasons will be very difficult to overcome. The main hurdles for you are

• You are effectively unemployed. The consulate will not be swayed by your statement that you manage the family business if you cannot prove it and may still be suspicious even if you could do that. You didn't mention that in your list of mistakes so it seems you do not realise how damaging this is. It means that you cannot show how you got the money to pay for this trip but also that you have no financial incentive to go back to the Philippines and could be considered at risk of immigrating to Spain.
• You are in a relationship with a Spanish citizen / resident. This is behind the “reasonable doubts as to your intention to leave the territory”. Even under the best of circumstances, this also means you could be tempted to stay in Spain and works against you. Worse, some of the choices you made make it look like you wanted to dissimulate that fact to the consulate, which also make it look as if you had been trying to (mis)use the short-stay visa to move to Spain.

Fiddling with the details of the trip (sponsorship, means of travel, etc.) won't change anything to the fundamentals of your situation. Applying immediately may further support the perception that you are desperate to go to Spain, which makes sense since your girlfriend is there but will still be treated as a red flag by the consulate.

There is nothing stopping you from applying again but from what you told us it sounds like you are in a difficult situation and a refusal is likely no matter what you do. In my opinion, you should only submit a new application if you can present very strong evidence addressing all the points raised in this Q&A.