You look great but:
1. It is easier to fall out of an English saddle - there is little pommel, little cantle and modest knee rolls. Always were a riding hat - you never know you might dismount sooner than you wanted to.
2 check saddle fitting. English saddles come in various shapes but the key measurements are length ie (16.5 inch to 19 inches and the width ie narrow, wide, extra wide.) If the saddle rests on the horse's spine it will hurt him - there must be at least two fingers of clearance along his spine. If the saddle leaves any rub marks on the horse's back after use, then it may be wrong size. Best to ask a saddler -if necessary a Western saddle fitter should know the principles.
Look up Riding Holidays in Spain, Purebred Spanish Horse Stud, Spanish tack shop and mail order, Doma Classica and Doma vaquera tuition training and holidays, trail riding in Spain and look for saddle fitting guide.
Also look up The Ideal Saddle.co.uk
On an English saddle , the riders weight is passed down onto the horse with a narrower foot print so if the saddle is wrong then the horse may react badly.
Have fun and take it easy.